Although the careers of high-ranking politicians and diplomats are usually objects of interest to historians, on account of their offering a compelling insight into the political events and processes of their times, we can also learn a lot from studying the careers of low- or middle-ranking ones. Those are the men who managed to climb up several rungs on the social ladder, sometimes even to considerable heights, but never high enough to shape political doctrines. Nevertheless, without them acting as go-betweens or factotum, the diplomatic and political machinery would not be able to function.

During the mid-1430s, one such person in the service of the Kingdom of Hungary was Peter of Crkvica. Although his moniker immediately reminds us of Cirkvena, Peter was not a member of this noble family of late medieval Slavonia; his place of origin can be identified as Crkvica (Cirkewcza), where in the fifteenth century stood a parish church dedicated to the Blessed Virgin. Its exact location has not been determined so far, but it was probably somewhere in the vicinity of the town of Križevci, in the territory of the late medieval Kingdom of Slavonia, a constituent part of the Kingdom of Hungary.

Peter of Crkvica enrolled in the University of Krakow in the summer semester of 1430, but probably did not attain any of the higher academic degrees. This was by no means unusual, considering that at that time most of the students would usually leave the university after graduating as bachelors of liberal arts, or even sooner. Although some of the documents style Peter as master, in those cases this title does not signify that he possessed the academic degree of master, but appears merely as an honorary usually used for the members of royal chanceries. In any case, in the supplications he addressed to the Pope, when asking to be awarded certain ecclesiastic benefices, Peter did not mention any academic degrees, which is an almost certain indication that he did not possess any. If he did, he would have certainly stated so, because candidates with higher education were generally favoured for such benefices, and they listed their titles scrupulously when applying for them.

Sometime before, or in 1445, Peter joined the entourage of John (János) Hunyadi, and managed to become his notary and chaplain. Notaries were low-ranking officials in medieval chanceries, and their tasks were not very glamorous.