The boat was laid on December 3, 1936 at Tosi in Taranto, launched on April 3, 1938 and put into service on June 30, 1938. It served first in the 44th and then in the 41st squadron of the 4th submarine group in Taranto. The following year it was relocated to Massaua , Eritrea , from where it was used in the Red Sea and Indian Ocean . In June and July 1939 it made a trip in the southwest monsoon to test operational tactics in heavy seas, but with moderate success. While all other Brin-class boats were moved to Massaua in 1940, Brin returned to Taranto, where it was assigned to the 42nd Squadron. From June 1940 it carried out four unsuccessful patrols in the Strait of Sicily and then near Crete , with one attacking aircraft being damaged.
On October 28, 1940, under the command of Luigi Longanesi Cattani , the boat left Italy for Bordeaux , where the Italian Navy had set up a base for their ocean-going boats. After it narrowly escaped two British destroyers near Gibraltar on November 4 , it had to be makeshift repairs in Tangier . From there it ran out on the night of December 13th. On December 18, 1941 there was an overwater battle with the British submarine HMS Tuna on the Gironde , which finally withdrew.
Brin made five patrols from Bordeaux . On June 13, 1941, it attacked convoy SL76 in the Azores , which was on its way from Sierra Leone to England, sank the British steamer Djurjura and the Greek ship Eirini Kyriakides and damaged two other ships. At the end of August, the boat returned to the Mediterranean, where it arrived in Messina on September 10, 1941 . From there, it carried out a number of unsuccessful endeavors over the next two years.
After the armistice of Cassibile , it was handed over to the Allies in Bône in September 1943 , who moved it with the Italian occupation first to Malta and then in October 1943 to Taranto. Between May 1944 and December 1945 it was used again in the Indian Ocean, where it was used by the Royal Navy for anti-submarine training off Ceylon . The boat was decommissioned on February 1, 1948 in Taranto and then scrapped.
