The brothers soon started the so-called Moravian Margrave Wars, fueled by disputes over inheritance and the destabilizing situation after the death of their uncle Charles IV in 1378.

Jobst and Prokop ruled Moravia together at that time and participated in the joint efforts of the Luxembourg dynasty to obtain the Polish and Hungarian crowns.

The Bohemian king Wenceslas IV also sought financial assistance from his Moravian cousins.

Jobst eventually contributed to his release, but Prokop soon succumbed to illness and died on 24 September 1405 in Brno.

However, due to his illegitimate origin, he could not assert the inheritance rights to the property and titles of his ancestors.