The county of Sayn- old churches was a former imperial immediacy territory of the Holy Roman Empire of the German Nation in the area of the Westerwald in today's Rhineland-Palatinate. The county was created in 1636 by inheritance from the county of Sayn.
Since the 12th century Altenkirchen belonged to the county of Sayn. After the line of the Counts of Sayn was extinguished in 1606, old churches came to the Counts of Sayn- Wittgenstein. After the death of the last Earl in 1636 the two remaining sisters inherited the county and finally divided them in 1652 in Sayn- Hachenburg and Sayn- old churches.
Johannette of Sayn was married in second marriage with Duke Johann Georg of Saxe- Eisenach. In this generation, the county remained until in 1764. Their heirs were the Margrave of Brandenburg- Ansbach, which was incorporated in 1791 Prussia. As a result of Reichsdeputationshauptschluss conclusion in February 1803, the county of the Principality of Nassau- Usingen was awarded the 1806 collected along with the Duchy of Nassau -Weilburg Nassau.
With the Congress of Vienna Sayn- old churches in 1815 and went back to Prussia as a circle Old churches in the Prussian Region of Koblenz. In 1946 it became part of Rhineland- Palatinate.