Apor was the first member of the short-lived Szentgyörgyi family, which originated from the Zala branch of the extended gens (clan) Péc, which had large-scale possessions in several counties of Transdanubia, in addition to other parts of the Kingdom of Hungary.
He was a son of Lucas III Péc, who served as ispán of Zala County in the 1290s.
He had four brothers, Desiderius, Stephen II, Egidius and Nicholas, who had no known descendants.
He was familiaris in the episcopal court of John Garai, Bishop of Veszprém.
[2] He was last mentioned by sources in 1360, when unlawfully seized the village of Maros from the Diocese of Veszprém, alongside his brother Desiderius.