In 1779 he joined the Royal Danish Army and quickly rose to the rank of Oberst.

From 1810 to 1821 William temporarily lived in his manor house at Hirrlingen near Rottenburg but more often in the Schloss Stetten in Remstal.

In 1815, on leaving office, William shifted to studying science and successfully practised as a physician.

The couple had six children, only three of whom reached adulthood: Since this was a morganatic marriage, on 1 August 1801 William renounced his descendants' claim to the throne of Württemberg.

This had an effect in 1921, on the death of William II of Württemberg, when his descendants were excluded from inheriting.