The parliamentary constituency 1 exists in Rhineland-Palatinate since the first state election law of 7 December 1950. Since then, the learned constituency different cuts.
In the course of preparations for the seventh state elections on March 21, 1971, the state parliament of Rhineland-Palatinate decided on July 7, 1970 to change the state election law. It was also made necessary by the dissolution of the Montabaur administrative district , which took place in 1968, and the district reform in Rhineland-Palatinate. By section 12 of the law, Rhineland-Palatinate has now been divided into six constituencies. The constituency 1 was reduced slightly, consisted of the districts of Altenkirchen (Westerwald), Neuwied, Oberwesterwaldkreis, Unterwesterwaldkreis, Rhein-Lahn-Kreis and was now awarded 15 members.
The next redistribution of the constituencies took place as early as 1972. On July 4, 1972, the state law amending the state electoral law was passed, as a result of which Rhineland-Palatinate was now divided into four constituencies. The constituency 1 consisted of the districts Altenkirchen (Westerwald), Ahrweiler, Neuwied, Oberwesterwaldkreis, Unterwesterwaldkreis, Rhein-Lahn-Kreis, Mayen-Koblenz and the independent city of Koblenz. Now the voters in the constituency could vote on 26 members of parliament.
After a minor change in the number of mandates in 1978, when constituency 1 received a mandate from constituency 4, the constituency of the state of Rhineland-Palatinate changed drastically in 1989. With the state electoral law in the version of December 20, 1989 , Rhineland-Palatinate was now divided into four electoral districts and 51 electoral districts. This classification has been valid since then with minor changes. In some cases, the names of regional authorities changed, and to a lesser extent, electoral districts also changed constituencies. Due to the new constituency division, exactly one direct mandate has now been assigned per constituency. The constituencies are now also differentiated by geographical names. The constituency of Betzdorf / Kirchen (Sieg) is now designated as constituency 1 . From the district of Altenkirchen (Westerwald) it includes the non-union community of Herdorf and the union communities of Betzdorf , Daaden and Kirchen (Sieg) .