 Pietro de' Crescenzi was born in Bologna in about 1235; the only evidence for his date of birth is the annotation "septuagenarian" in the "Ruralia commoda", dated with some certainty between 1304 and 1309.He was educated at the University of Bologna in logic, medicine, the natural sciences and law, but did not take his doctorate.Crescenzi practiced as a lawyer and judge from about 1269 until 1299, travelling widely in Italy in the course of his work.