Cracks in the cooperation between Poland and Lithuania after the death of Vytautas in 1430 had offered the Knights a revived opportunity for interference in Poland. Władysław supported his brother Švitrigaila as grand duke of Lithuania, but when Švitrigaila, with the support of the Teutonic Order and dissatisfied Rus' nobles, rebelled against Polish overlordship in Lithuania, the Poles, under the leadership of Bishop Zbigniew Oleśnicki of Kraków, occupied Podolia, which Władysław had awarded to Lithuania in 1411, and Volhynia. In 1432, a pro-Polish party in Lithuania elected Vytautas's brother Žygimantas as grand duke, leading to an armed struggle over the Lithuanian succession which stuttered on for years after Władysław's death.