Complex sentence: Zápolya used the turbulent times of his era to enrich himself and secured a power base in Transylvania, later he was tasked with defeating the peasant rebellion of 1514 led by György Dózsa which he did showing extreme cruelty.
Split into simpler sentences: Zápolya used the turbulent times of his era to enrich himself and secured a power base in Transylvania. When he was tasked with defeating the peasant rebellion of 1514 led by György Dózsa he used extreme cruelty.