Under his reign, the Cirksena family acquired on 18 April 1662 the hereditary title of Imperial Prince.

This conflict was based on compensation East Frisia had to pay under the Treaty of Berum, in exchange for the acquisition of the Lordships of Esens, Stedesdorf and Wittmund.

Under the pretext of enforcing the payments, the Bishop of Münster marched his troops into East Frisia in 1663.

Colonel Elverfeld conquered Hampoel and the Sconce at Diele on East Frisia's southern border.

This gave him the proper rank to marry a Princess of Württemberg (German: Ebenbürtigkeit), and so the marriage was finally performed on 10 May 1662 in the city of Stuttgart.