Electorate of Mainz
In the 11th Century, the Werratal was the boundary between the Electorate of Mainz and the Guelph dukes and therefore contested. Jestädt itself belonged to the but it later passed to the . Its new owner, Otto von Northeim, the Duke of Bavaria, however, died in 1083 before he could take formal possession. His son, Siegfried III, "Graf" [ Count ] von Boyneburg, finally gained the control of Jestädt.