frederick's son frederick ii, duke from 1499, again inherited the duchy of brzeg in 1520. the protestant reformation was introduced in the duchy as early as 1522, decisively promoted by the theologians caspar schwenckfeld and valentin krautwald, and the population quickly turned lutheran. this led to conflict when, after the death of the bohemian king louis ii at the battle of mohács in 1526, the lands of the bohemian crown including the legnica fief were incorporated into the habsburg monarchy of the catholic king ferdinand. in turn, duke frederick ii signed an inheritance pact with the hohenzollern elector joachim ii hector of brandenburg, a cousin of his second wife sophia. however, king ferdinand i, rejecting any hohenzollern influence within the habsburg lands, declared the agreement null and void.