[7] Until 1207, Peter disappeared from contemporary sources, it is presumable that he supported the rebellious Duke Andrew against King Emeric, thus unable to hold any political offices in the royal court.

[1] When Andrew II left Hungary for a new campaign against Galicia, a group of Hungarian lords, taking advantage of the King's absence, captured and murdered Queen Gertrude and many of her courtiers in the Pilis Hills on 28 September 1213.

[11] According to the contemporary reports, Peter personally slaughtered the Queen, while Palatine Bánk Bár-Kalán, the Kacsics brothers (Simon and Michael) and other lords were also involved in the conspiracy.

Formerly linguist János Horváth argued the chroniclers in fact referred to the coeval Felician Záh's assassination attempt (1330) against Charles I of Hungary, when describing Gertrude's death.

[14] József Katona's Bánk bán (which was set to music by Ferenc Erkel), where Peter appears as Ban Petúr, also preserved and spread this version.

[16] It is much more likely that the Hungarian lords led by Peter, who were aggrieved at Queen Gertrude's favoritism towards her German entourage, feared to permanently lose their court positions and influence.

Formerly, Gertrude's two brothers, Ekbert, Bishop of Bamberg, and Henry II, Margrave of Istria, fled to Hungary in 1208 after they were accused of participating in the murder of Philip, King of the Germans.

[21] However, Peter's accomplices, including Palatine Bánk, did not receive severe punishments, due to the current political situation and Andrew's power instability.

[23] According to a royal charter issued in 1237, Béla IV, now as king, donated Peter's former lands to the newly founded the Cistercian Bélakút Abbey, which belonged to the Archdiocese of Kalocsa.