The fortress Jülich describes the entirety of the fortifications around the Rhenish town of the same name , which existed between 1547 and 1860 in the early modern period. It is one of the oldest and most unusual examples of fortress architecture of this era north of the Alps. Its remains with a Renaissance citadel and Napoleonic bridgehead represent one of the most important ensembles of early modern defense architecture in Germany.
Ancient and Middle Ages
Since the settlement was founded as a Roman vicus along the Roman road Boulogne - Heerlen - Cologne , it had had a strategic importance, as it controlled one of the few passable Rur crossings and a bridge probably already existed in Roman times. For this reason, Ivliacvm was expanded into a fortified castle in the 4th century, which probably had sixteen towers and enclosed the area around today's market square. This fortification, originally intended to ward off barbaric incursions from the east, fell into Frankish hands when the Romans withdrew in the 5th century and became the nucleus of Jülichgau , from which the county and in the 14th century the duchy of Jülich emerged . The castle of the Jülich lords is to be found in the western part of the fortification , which presumably used a section of the Roman wall as an outer wall. In today's district of Altenburg, a moth emerged in the 12th century , which was destroyed again in the 13th century. At the turn of the 13th century to the 14th century, the city was completely re-fortified, which already encircled a considerable part of today's old town. It was a Gothic fortification that was set up to defend the crossbow. Relics of this construction phase are the Hexenturm and a preserved section of the city wall inside the building of the block, which lies between Stiftsherrenstrasse and Großer Rurstrasse (backyard plots at Stiftsherrenstrasse 7 and 9, access is limited).
In the meantime the dukes of Jülich had become rich and powerful, the Jülich Land was part of the United Duchies of Jülich-Kleve-Berg . Their ruler, Duke Wilhelm V , had great ambitions and wanted to extend his rule to the Duchy of Geldern , too he had an inheritance claim after the ruling house there died out. Emperor Charles V also considered himself a legitimate heir, and the two rulers clashed in the Geldern feud in 1543 . The duke was defeated by the emperor because the French allies with him did not want to stand up for him. He submitted to the emperor and had to give him funds in the Treaty of Venlo and marry a Habsburg woman. A major reason for the defeat was the rapid conquest of the ducal fortresses, which were still arrested in the Middle Ages and no longer able to cope with the modern artillery. The Duke came up with the plan to develop several cities under his rule into modern state fortresses and, in some cases, residential cities - Düsseldorf as the residence of the Duchy of Berg , Orsoy as the main Klevian arsenal and Jülich as the residence of the Duchy of Jülich. The city of Jülich had been handed over to the emperor without a fight and therefore remained undestroyed, but the construction of a new, modern city fortification in a circular system had already started. But that was no longer enough for the ambitious Duke, he had a completely new ideal city in mind. He asked around for a suitable builder and fell in with Alessandro Pasqualini from Bologna , an accomplished architect and fortress builder who had been working in the Netherlands for a long time. Wilhelm put him in his service and entrusted him with the expansion of the three large state fortresses and residential cities.
The main focus was on Jülich, where a perfect, completely new city was to be created according to the taste of the Renaissance - an ideal city . The medieval city was still standing, so initial planning had to take it into account. But as early as 1547, almost the whole city burned down in a single night (from May 25th to 26th), and nasty tongues suspected arson - only the area around the Hexenturm and today's Kleine Rurstrasse was spared. In any case, the way was now clear for a complete rebuilding according to ideal criteria, and Pasqualini soon presented his plans. The design envisaged a huge citadel with four bastions on the north side of the city , with an edge length of around 500 meters from bastion point to bastion point and a double fortification, in the center of which the ducal residential palace was to be located as a palazzo in fortezza , a much discussed but rare at the time executed concept. The city was constructed as a stretched pentagon, two of the five corners were to be covered by the citadel, while the rest was protected by a modern bastion fortification. The plan of the city followed ideal points of view, all streets were wide and straight and directed towards the citadel, in order to make it possible to rule the city from it. The houses followed strict building regulations, which should reduce the dangers of fire or street fights. So was z. For example, the width of the street was calculated so that the rubble of a collapsed house only blocked half of its width and the other half remained free for through traffic. All houses were to be built in stone to minimize the risk of a devastating city fire.
As can be seen from the plan, the fortification of the city is divided into two clearly delimited areas: the citadel with the ducal castle and the actual city fortifications. It can be assumed that the original plan was initially to be implemented; the shifting of the palace chapel from the central axis of the east wing suggests that the originally larger building had to be reduced in size. In the end, the citadel was only about half as large as planned, and the city fortifications now had four bastions instead of three, one of which was a half-bastion, and was connected to the reduced citadel with two additional irregular walls. Nevertheless, when it was completed around 1580, the fortress was considered the most powerful and modern in all of Europe. It consisted of the following elements, which remained almost unchanged until the end of the fortress period and were modernized several times and expanded with numerous porches and superstructures:
Citadel (preserved to this day)
- Bastion Wilhelmus or Citadel Bastion No. I.
- South-eastern bastion of the citadel, only slightly threatened and comparatively poorly developed
- Bastion Marianne or Maria Anna , also Citadel Bastion No. II
- North-eastern bastion, most endangered and hardest fortified because of its location opposite the Merscher Höhe
- Bastion St. Salvator , also Citadel Bastion No. III
- Northwestern bastion, also seriously threatened and well developed
- Bastion St. Johannes , also Citadel Bastion No. IV
- Southwestern bastion, little endangered and therefore poorly developed
City fortifications (only remnants left)
- Bastion St. Sebastianus or City Bastion No. I.
- Northwestern bastion of the city fortifications (corner of Kuhlstrasse / Schützenstrasse), only designed as a half-bastion due to its proximity to the citadel and the less threatened position. Later provided with a raised cavalier to protect the Rur front.
- Bastion St. Eleonore or City Bastion No. II
- The westernmost bastion (bend in Schützenstrasse near the Hexenturm) protected the Aachener Tor and the Rur crossing
- Bastion St. Jakob or City Bastion No. III
- Southernmost bastion (corner of Bongardstrasse / Am Aachener Tor), rather little threatened. Protected the Aachen Gate and the Bongard Gate
- Bastion St. Francis or City Bastion No. IV
- Eastern city bastion (corner of Große Rurstraße / Poststraße at the New Town Hall), protected the Kölntor
The ramparts and bastions were made of earth, framed by facing walls made of bricks, which were up to five meters thick on the field side. Behind the curtain wall on the field side was a system of barrel vaults that divided the earth of the main wall into small portions and prevented the earth from leaking out in the event of a breach in the wall, which delayed the emergence of a passable breach through which a possible enemy would have stormed the wall can. The fortification of the citadel was designed to be much stronger than that of the city, the walls there were twelve to fifteen meters high instead of just eight to ten meters for the city wall, and at up to 42 meters they were also significantly stronger than the maximum 20 meters thick City wall. Both the city wall and the citadel wall were sloped in the lower part, which strengthened the wall and caused projectiles to ricochet from above in the direction of the enemy. Inside the bastions ran a system of bomb-proof casemates that led to the cannon yards in the withdrawn flank positions of the bastions, the citadel also had communication corridors behind the front curtain wall and partly behind the courtyard wall, which were built in later.
Both the citadel and the city fortifications had several gates, with only the city gates bearing names.
- Kölntor : The Kölntor formed the eastern entrance to the city from the old Roman road towards Cologne . At a later time it was secured by an upstream ravelin . Along with the Aachener Tor, it was the most important gateway to the city, especially for through traffic.
- Bongard Gate : The Bongard Gate was never one of the main gates, but rather intended as a failure and supply gate. It broke through the southeastern city wall and led to the Ravelin in front of this front. It disappeared around 1633.
- Aachener Tor or Rurpforte : The south-western entrance to the city from the Rurbrücke. Next to the Kölntor the most important city gate and strongly secured by several upstream works.
- Dürener Tor : The Dürener Tor was on the north side of the city between the citadel and the city bastion I. It was never of great importance and disappeared sometime in the 17th century.
The citadel had a main gate in the north and south, which connected it to the city and to the northern side of the field. At a later time, gates to the west and east were also built, which, however, were not used for through traffic, but only for communication with the eastern and western foothills.
The first practical test for the new fortress came as early as 1610. In the course of the Jülich-Klevian succession dispute after the dynasty had died out, imperial troops occupied the fortress, as Emperor Rudolf II took the position that the fiefs would come to him at the end of the ducal line fall behind. Both Brandenburg-Prussia and the Electorate of Palatinate asserted inheritance claims and war broke out.
The siege of 1610
Dutch troops allied with the Brandenburgers and Palatinate, reinforced by troops from England, France and the Protestant Union, moved up to the fortress under the leadership of Moritz von Oranien-Nassau and Christian von Anhalt and besieged them from July 28th , accompanied by a large number of international observers, who followed the operations against what was then the strongest fortress in Europe. The besiegers, allegedly 18,000 men on foot and 3,000 horsemen with 48 guns, adorned the fortress with a ring of entrenchments and took up position on the Merscher Höhe, an elevation northeast of the citadel, from which one can get a good overview of what was happening and also had a good firing position to attack the citadel. The elevated position made it easy to shoot into the fortress from there, and the high northeast tower of the castle was said to be a particularly popular target. Larger camps were located at Barmen and Broich (Moritz von Oranien) and at Stetternich and Bourheim (Christian von Anhalt), while the quarters of French auxiliary troops were at Koslar. The 2500-strong fortress garrison had built a few additional outbuildings in front of the field side of the citadel, as the attack was only directed against them.
On the night of July 31st to August 1st, the actual attack began by digging trenches against the citadel. On August 4th a battery of four guns began to bombard the fortifications, five days later another battery with nine guns, and on August 14th another battery of four guns joined them. The focus of the attacks was the Ravelin II in front of the field side of the citadel, which was able to repel a first assault, but fell into the hands of the besiegers on the second. The Kontregardes in front of Citadel Bastions II and III also fell quickly, and the besiegers were able to start building batteries in front of Citadel Bastion II. Cash and food soon became scarce in the fortress, and the fortress commander and Jülich bailiff Johann von Reuschenberg zu Overbach had neglected to stock up on sufficient supplies. The Imperial Commissioner Archduke Leopold had left the fortress in the meantime, but his silverware was cut into small pieces and stamped and given out as emergency cliffs for the soldiers.
On August 26th, under cover of night, the besiegers crossed the trench, which they had partially filled, and called on the defenders to surrender for the first time. The commandant asked for three days to think about it, but refused, whereupon the besiegers began the attack on Citadel Bastion II on August 27th. Miners undermined the ramparts and broke through the cladding wall of the bastion on August 28th, and the next day they penetrated the earth behind. On August 31, the work of the miners and 200 rounds of the siege artillery had laid a wide breach, and it was only a matter of time before a practicable breach would enable an assault on the citadel. Accordingly, the defenders surrendered on September 1, 1610. The survivors were granted a deduction under honorable conditions.
In the first years after the siege, half of the crew consisted of Brandenburg soldiers and half of the soldiers from the Palatinate-Neo-Burgess. When the two victorious princes began to quarrel in 1614, the Dutch placed them in trusting hands under their protection, and Serjeant Major Frederik Pithan from the Dutch Nassau regiment became the new fortress commander. The new men laid before the town and the citadel of some new outworks, primarily time typical Horn works in Erdbauweise. The main focus was on the north side of the citadel, which has been shown to be the most threatened. In the meantime, Brandenburg and Palatinate had agreed in the Treaty of Xanten on a division of the United Duchies: The Palatinate received Jülich and Berg, while Brandenburg received Kleve and the counties of Mark and Ravensberg . However, the Dutch garrison stayed in the city even after the treaty.
The siege of 1621/22
With the outbreak of the Thirty Years War , the city again became the focus of interest. The resurgence of fighting between the Dutch States General and Spain in the course of the Eighty Years' War marked the beginning of a new siege. Both sides had signed a twelve-year armistice in 1609, which expired that year. This immediately led to renewed hostilities, and the Spaniards raised an army to invade the Netherlands from Jülich and Kleve. General Ambrosio Spinola was in command of 40,000 Spaniards, of whom a delegation of 7,000 infantrymen and 700 mounted men were to attack under the command of Count Heinrich von dem Bergh Jülich. The Dutch under Moritz von Orange also called their troops to arms, and their army gathered at Schenkenschanz . The main Spanish army initially moved unexpectedly in the direction of Wesel and not directly against Jülich. Spinola apparently did not want to fritter away his troops unnecessarily in a long siege and instead sought the decisive battle. The Dutch withdrew 1,000 soldiers from Jülich immediately before the start of the hostilities, which weakened the crew dangerously.
On September 5, the besiegers set up camp on the Galgenberg not far from Broich , and on September 8, Ernst von Isenburg-Grenzau came with another 4,000 men and eight guns. Again the city was cut off from the outside world by a ring of entrenchments, and the Spaniards attacked the citadel above all from the Merscher Höhe, as in the previous siege. The strategy of the besiegers evidently relied on starving the fortress or tempting it to surrender by the failure of any hope of relief. The 2,500-strong crew under the now 72-year-old Frederik Pithan offered tough resistance from the reinforced positions in front of the citadel and repeatedly carried out failures in order to disrupt the work of the besiegers. In the meantime, Spinola himself appeared in front of Jülich and asked the defenders to surrender on September 24, but they refused. Although Pithan was well aware of the situation, he was far from thinking of giving up. A particularly successful sortie on October 5th led the cavalry of the defenders into the attackers' camp. A fire broke out there, diverting the attention of the Spaniards and allegedly causing considerable damage to the camp. As with the siege in 1610, the defenders had failed to bring the contents of the magazines in the area to the fortress in time, so that supplies soon ran out.
There was no prospect of relief because the Spaniards blocked the Dutch army at Kleve so that Moritz von Orange could not send any help. Again it came to the issue of Token . When Spinola's army opposed the armies of the States General during a scanning advance in December 1621, the hope of relief was finally extinguished, and Moritz von Orange released his soldiers into the winter quarters, so that Spinola himself appeared before Jülich with his entire army. He had a raised cavalier fill up, from which the Spanish batteries had a much improved firing position, and intensified the bombardment. The occupation was initially unimpressed, although food shortages took on more and more dramatic forms and diseases began to rampant in the city. Pithan refused the surrender twice and gave the Count von dem Berg to understand that one should wait until Easter before considering surrender. In the end, however, he decided on January 17, 1622 to start negotiations if relief or food did not arrive within twelve days, and on February 3, 1622 he handed Jülich over to the Spaniards, whereby he and his 2,000 soldiers were granted the honorable withdrawal. Apparently, however, his superiors were of the opinion that he had not done the utmost in defense, and Pithan was released from his regiment because of the handover of Jülich.
For the remainder of the war, the Spaniards occupied the fortress and carried out some renovations and extensions. Among other things, they probably moved the Aachen Gate from the extension of the Hexenturm to its current position around 1648 . Allegedly, the Spanish were not very popular with the population and were seen as oppressors. The Spaniards did not leave Jülich until 1660 and gave their property back to the Palatinate.
In 1678 the city was blocked by French troops in the Franco-Dutch War , but no serious attack took place. From 1693 the Palatinate and later the Bavarians carried out considerable extensions to the fortress. The citadel was given a four-part upper wall system (cavaliers) and was surrounded by a wreath of advanced ravelins and contregardes , and a glacis was also created. The city received similar outbuildings, although not of the same strength as the citadel, as this clearly represented the most threatened position and enabled the entire city to be ruled.
The 18th century
Around 1741 and from 1756 to 1762 French troops occupied the city during the Seven Years' War with the permission of the Duke, and again from 1772 to 1778, this time without permission. In the late 18th century the fortress fell into disrepair, and when the French advanced on it after the Second Battle of Aldenhoven in 1794, it was surrendered without a fight on October 3rd. With the establishment of the Rhine border, Jülich (now called Juliers a French mairie in the Département de la Roer ) acquired a new meaning as a stage fortress on the important military route from the Rhine to the French metropolitan area. Around this time a ski jump was built on the Merscher Höhe, which is now commonly referred to as the Sternschanze . Presumably it was built by the French immediately after taking possession of the city as an emergency measure in earthworks to additionally secure this weak point. Their remains were found during the excavation work for a new building area at the end of the 20th century near the relocated Lich-Steinstrasse and led to the naming of the Sternschanze street . The plans and excavation findings identify it as a redoubt that is open to the rear and dominates the Merscher Höhe and should make it difficult for any besiegers to settle on the Merscher Höhe most suitable for attacking.
The French forged far-reaching expansion plans, which they immediately began to implement, especially after Napoléon Bonaparte came to power . The imperial fortress doctrine no longer saw the fixed places only as a defensive weapon, but rather as a firm support for the mobile field army. Accordingly, the plans provided for the area dominated by the fortress to be expanded enormously so that it could serve as a retreat, camp and base of operations for a strong army. In addition, a wreath of field fortifications with entrenchments should be placed around the city in strategically important places in order to be able to dominate their surroundings and to make it difficult for an attacker to approach. They were also intended to serve as a support and fortification for an imperial army operating from Jülich, but most of the planned facilities remained a project. In addition, many other smaller expansions and improvements were undertaken, in 1811 the powder magazine was completed on the citadel bastion of St. John, and in 1806 his younger brother had already started on the bridgehead.
However, the key positions of the enlarged facility were clearly to be found at the Rur crossing to be protected and on the Merscher Heights, the possession of which enabled the attack on the citadel. The south-western front with the river crossing was covered by the newly created huge bridgehead (from 1799), and a new Rur bridge (from 1806) was built, which was designed as a lock bridge. It was used to dam the river and flood the area south of the city, making it impossible for any attacker to enter. Another large project was the construction of three large forts on the Merscher Höhe, which should make it impossible for any besiegers to approach the fortress from there without switching them off beforehand. They were started in 1804, with Emperor Napoleon I himself laying the foundation stone, the older Sternschanze had to give way to the new buildings and was leveled. However, when the Wesel fortress fell into French hands in 1806, priority was given to expanding Jülich and work was stopped. The three forts never got beyond the excavation work for trenches and foundations, which were still clearly visible until the second half of the 20th century and also appear in plans and aerial photographs. Even after that, Napoleon personally provided considerable funds for the expansion of the fortress (up to a million francs in 1806). In addition, the French began to install forward lunettes in order to be able to better control the fortress front. Initially, only the lunettes in the east, south and west were created, which were later designated with the letters D-G, since the forts on the Merscher Höhe were supposed to protect the northern area. Only later, when the expansion of the forts came to a standstill, the lunettes A – C were also created, like the others mostly in earthworks.
The siege of 1814
Apart from the completed bridgehead, the work had not progressed very far when Napoleon's defeat in the Battle of Leipzig forced the French to retreat behind the Rhine in 1813. Jülich did not surrender, but was blocked by Prussian, Danish, Mecklenburg and Swedish associations for the winter in 1814. There was hardly any fighting; the besiegers mainly wanted to keep the French in the fortress. The hardships winter of the siege was described by Johann Wilhelm Schirmer in his memoirs. The Jülich Fortress did not do justice to its intended purpose by the French. There was neither a strong field army to serve as support, nor did it prove to be an obstacle to the operations of the Allies, who built another bridge over the Rur a few kilometers south of the city and thus simply bypassed the fortress. The crew was far too weak for effective failures, and the commander Brigade-General St. Loup rejected a handover offer made at the end of March, pointing to the good supply situation. On April 28, 1814, after information was obtained from Paris, the defense surrendered, and on May 4, the French withdrew.
Jülich comes to Prussia
With the peace treaty in 1814, Jülich came to Prussia , which carried out further expansions. The forts that had been started on the Merscher Höhe were not completed, but all other buildings started by the French were completed. Furthermore, seven bezels with the designations A – G were placed around the city as advanced defensive positions in order to be able to control their surroundings more effectively. Some had already been built by the French, but since the forts to cover the citadel were not built, three new ones (A – C) were added to close the dangerous gap on the northern front. No fewer than five of these outbuildings covered the citadel in all directions, the other two protected the city from the south. There was also the Neue Flesche , which protected the large space between the bezels C and D on the eastern flank of the citadel. The location of the lunettes A, B and C can still be read from the course of Artilleriestraße, and the course of Wilhelmstraße follows the former covered path from Kölntor to lunette D. The property of lunette F can still be seen in the cadastre today, and the Today a public road leads to this outwork (at the lunette). There are also some remains of earth from bezel A.
In 1831 the fortress was put on alert because of the revolution in France, probably also because of the struggle for freedom in Belgium . In 1833, however, the order to disarm was followed, and until the demolition in 1860, only maintenance work was carried out.
Siege exercise and demolition
In the middle of the 19th century, weapon technology developed rapidly. With the improvement of metallurgy and production technology, it became possible to mass-produce accurate and long-range breech loading guns and rifles with rifled barrels. Since one was no longer dependent on bullets as projectiles, but could use twist-stabilized long projectiles, the penetration power of the artillery grew enormously. Smaller and older fortresses like Jülich were no longer able to cope with this new development, and the Prussian cabinet decided in 1859 to abolish the fortress. This met with resolute resistance from the citizens, who owed their livelihood to a not inconsiderable part to the maintenance of the fortifications and the orders from the garrison, and the citizens submitted petitions to King Wilhelm asking for the fortress or at least the garrison to be preserved . Jülich remained a garrison town and a non-commissioned officers' school was set up in the citadel, which owes its preservation to this circumstance.
In connection with the imminent abolition of the fortress, the Prussian high command scheduled a large-scale siege exercise in Jülich for the period from September 8 to 29, 1860, during which the new weapons were to be tested in practice against a contemporary fortress. The latest rifled breech- loading guns from Krupp were used, which fired explosive shells, as well as the new Dreyse needle rifle , which was to contribute so decisively to the success of the Prussians in the German War of 1866. New firing methods and attack tactics were tried out in practice on the outworks, but also on the citadel itself, and the Great Breach in the northern face of the Marianne bastion also emerged. It turned out that the new weapons made the attack on a fortress like Jülich much easier. Their significantly increased firepower, rate of fire and accuracy compared to the old smoothbore guns shifted the weight in the siege war significantly in favor of the attackers, and the new, precise and far-reaching rapid-fire handguns also contributed to the fact that in Europe between 1860 and 1880 there was a great fortress death. Small facilities like Jülich could no longer withstand the new weapons in a real siege long enough to justify their costly maintenance any longer, and in the following years they relied on much larger fortresses with a network of mutually supporting forts. How devastating those Weapons from the late 19th century were effective against older fortresses, the French found out in the Franco-Prussian War , when the German fortresses like Strasbourg were able to conquer much faster than expected.
In the years 1859 to 1861, most of the fortifications around Jülich were demolished as planned. All the outworks and most of the city fortifications fell victim to this, only the citadel and the bridgehead remained. However, they suffered severe damage in World War II and were put to new uses (see respective special articles).
- Johann von Reuschenberg zu Overbach , before 1609–1610
- Frederik Pithan , Serjeant Major, States General, 1614–1622
- Johann Edmund Waldbott von Bassenheim, major general, Electoral Palatinate, before 1677–1679
- Freiherr von Leibeck (also: Lybeck, Libeck), General Feldzeugmeister, Electoral Palatinate, 1679/80, 1689
- Johann Raab von Haxthausen (1715–1732), baron, field marshal-lieutenant and field warden, Electoral Palatinate
- Jacob Heinrich Graf von Harscamp, General, Electoral Palatinate, 1732
- Franz Anton Bawyr von Frankenberg , Lieutenant General, Electoral Palatinate, 1733–1735
- Johann von Pfalz-Birkenfeld , General Feldzeugmeister, Electoral Palatinate, 1753 (Deputy: Commandant Jarris de la Roche)
- N. von Schutter, Lieutenant Colonel, 1815
The following remains of the city fortifications still exist:
- Stadtbastion I St. Sebastianus : Bumps in the area of the corner of Schirmerstrasse and Bastionsstrasse, which indicate the course of the ditch.
- City bastion II St. Eleonore : Bumps in the block development
- Aachener Tor : The archway and the curtain wall of the curtain wall adjoining it in the south have been preserved up to the city bastion III, and the moat along today's secondary school still exists
- City bastion III St. Jakob : almost completely preserved underground, extensive casemates .
- City bastion IV St. Franziskus : remains of a moat behind the New Town Hall, some underground vaults are still preserved
- Swan pond : originally created as a fire fighting and drinking water pond
- Promenade : largely follows the course of the old city fortifications, which can be read from it.
- Connection of the city moat to the citadel moat : both connections of the city moat can still be clearly identified, at the western connection under the Bonhoefferhaus there are still remnants of the former lock system in the Kontereskarpe.
- On the Lunen / Kolfs Insel : The new development area Kolfs Insel is on the property of the Lunen F.
- Wilhelmstrasse : The Wilhelmstrasse follows the course of the covered path to the lunette D, the tax office on both sides of the street is on the property of this Vorwerk.
Remains of the outer works of the citadel:
- Kontregarde III in front of the St. Salvator bastion, substantial wall and moat remains along the northwest side of the moat
- Kontregarde II in front of the Maria Anna bastion, a flat earth wall at the edge of the ditch in front of the bastion point
- Ravelin I (also Ravelin Lyebeck ) in front of the Ostkurtine, significant remains of the casemate under the kindergarten, partly expanded as an air raid shelter
- Ravelin II in front of the north tower, wall and moat remains on both sides of the access road
- Ravelin III (also Ravelin Judas) in front of the Westkurtine, considerable remains of earth and lock system in the ditch area. The ravelin was an earthwork and was not built over; it could be restored with relatively little effort
- Ravelin IV in front of the postern on the city side, size indicated in the paving, remains of the gatehouse
- Bezel A at the western end of Artilleriestraße, considerable remains of earth
- Lunen C at the eastern end of Artilleriestraße, today the guest house of the research center stands on the property .
- Forts on the Merscher Höhe: the excavations that had begun were clearly visible until the 1970s, then they were destroyed by the cemetery expansion and the construction of the technical college. Only on the post site near the transmitter of the short wave center are small remains that are not publicly accessible.
- Büren, Guido von; Kupka, Andreas: Castle and Citadel Jülich . 2004. ISBN 3-7954-1482-2
- Eberhard, Jürgen : The Citadel of Jülich , Verlag Jos. Fischer, Jülich 1993. ISBN 3-87227-044-3
- Neumann, Hartwig : City and fortress Jülich on pictorial representations , Bonn 1991. ISBN 3-7637-5863-1
- Neumann, Hartwig: The Citadel Jülich: A Walk Through History . Publishing house Jos. Fischer (Jülich), 1971.
- Neumann, Hartwig: The Jülich bridgehead . Publishing house Jos. Fischer (Jülich). 1973.
- Neumann, Hartwig: The end of a fortress . Publishing house Jos. Fischer (Jülich), 1987. ISBN 3-87227-016-8
- Neumann, Hartwig: Citadel Jülich: Great art and construction guide . Publishing house Jos. Fischer (Jülich), 1986. ISBN 3-87227-015-X
- Virtual tour through a reconstructed 3D model of the city and fortress
- Overlay for Google Earth showing the location of the fortifications
- Timeline Jülich
- Jülich bridgehead park
- Corps de la Place de Juliers
- Jülich history association
- Website of the city of Jülich
- Citadel Museum
- Illustration by Frans Hogenberg from 1621: Actual illustration of the famous Vestung Gulich ... ( digital copy )
- Illustration by Frans Hogenberg from 1610: Occupation of the Vestung Gulich started on the 28th Juij resulted on the 2nd of September 1610 ( digitized version )
- AHVN, Vol. 18, p. 31.
- LAV NRW, Rhineland Department, 141.01.01-04 Generalgouvernement of the Lower and Middle Rhine, 1408.