Gleichen

The counts of Gleichen were a Thuringian noble house first documented in 1089 as counts of Tonna and seated at Graefentonna. In 1130 the archbishops of Mainz enfeoffed them with Gleichen Castle near Gotha, which gave the family its name and its County of Gleichen.

As Mainz Vogts over Erfurt from 1120 to 1290 and the archbishopric's dominant feudatories in the Eichsfeld, they were Mainz's chief agents in central Thuringia until they sold their Eichsfeld estates back to the archbishopric in 1294. In 1342 they became Vogts of Hersfeld Abbey over Ohrdruf, where they built a compact lordship, and in 1590 they moved their court there and built Ehrenstein Castle.

They also held fiefs of the margraves of Meissen and in 1583 inherited the immediate counties of Pyrmont and Spiegelberg. The comital line died out in 1631. A younger line, the barons von Gleichen attested from 1418, outlived it and in 1732 inherited the Greifenstein estates of the extinct lords of Russwurm.