His father, Bernhard III (1459–1526) was president of the Reichskammergericht from 1510 to 1520.

[1][2][3][4] In 1561, Wilhelm officially converted the County of Eberstein to Protestantism.

He had been unofficially promoting the Evangelical faith for some time.

A tombstone depicting Wilhelm and his wife, has been preserved in the St. Jakob church in Gernsbach.

[5][6][7] On 6 November 1522, he married Countess Johanna of Hanau-Lichtenberg (1507–1572),[8] the eldest daughter of Philipp III, Count of Hanau-Lichtenberg (1482–1538) and Margravine Sibylle of Baden (1485–1518).