[1] From the 12th century they ruled extensive territories in the Rhine Main area from their castle in Eppstein, northwest of Frankfurt, Germany.
Between 1180 and 1190, the Archbishop of Mainz enfeoffed Eppstein Castle, along with neighboring district courts and villages to Gerhard III of Hainhausen.
[2] Gerhard changed his name to Eppstein and already having control of the present-day district of Offenbach, became the first in the line which was soon to become one of the most influential families in the Rhine Main area.
In the struggle between the Emperor and the Pope, Archbishop Siegfried III took sides with the anti-Staufer group which played an important part in the beginnings of German federalism.
The secular Eppsteiners, by purchase, marriage and enfeoffment, acquired extensive territories and rights between Middle Rhine to the Vogelsberg hills and between the Lahn River to the Odenwald.