He was an illegitimate child born (probably at Hârlău) to Ştefan cel Mare. His mother was Maria Răreşoaia of Hârlău, whose existence is not historically documented but said to have been the wife of a wealthy boyar fishmonger nicknamed Rareş—“rare-haired”, balding; Rareş thus was not Petru’s actual name but a nickname of his mother’s husband. Petru exhibited many of his father’s qualities: ambition, daring, bravery, piety, artistic taste. However, he was marked by inconstancy and a lack of political instincts.