He was also a descendant of Stephen the Great, through the bloodline of his great-grandfather Petru Rareș. His uncles, Simion's brothers, were Gheorghe Movilă, the Metropolitan of Moldavia, and Ieremia Movilă, who also ruled Moldavia before and after the first reign of Simion. Petro Mohyla's mother, Marghita (Margareta), was the daughter of a Moldavian logothete, Gavrilaș Hâra.[3][4][5] Petro Mohyla's sister Regina married prince Michał Wiśniowiecki, and their son Jeremi Wiśniowiecki, was Mohyla's nephew and supporter even though he converted to Catholicism in order to marry a Roman Catholic princess and thus inherit the Polish crown.