Peter's father was Mihailo (Michael) Petrović of Suraklin (Zraklin/Tisovica), a representative of Vrbas County in the Hungarian Diet of Rákos from 1505.
[1] Peter only had sisters, including Anna who was married to Sigismund Levai with whom she had several daughters and after the death of her first husband, she got re-married to Francis Kendi.
Count Petrovics first appeared on the historical scene after the death of Jovan Nenad, on the side of John Zápolya, with whom he had familial ties.
[2] In 1556, using Serbian troops, he attacked the units of Ferdinand I, Holy Roman Emperor and in doing so achieved the return to the Hungarian throne of John Sigismund Zápolya.
[10] Petrovics had in the previous years been pressed to leave the southern region of Temesvár (today's Timișoara), and had settled in the northern country.