Petros De, Or Pietro Delle Vigne Vineis, an Italian jurist, born in Capua, committed suicide in Pisa in 1249. He was educated at Bologna, and became known by accident to the emperor Frederick II., who raised him from one office to another, and at last made him his chancellor. In this capacity he defended his master both in writing and orally against Popes Gregory IX. and Innocent IV. He was probably present in 1245 at the council of Lyons, before which Frederick was cited, but seems to have been silent; and it was surmised that he had betrayed the emperor's interests. The popular story of his time was that he was accused of attempting to poison his master, and was led on an ass through the streets of Pisa and cast into prison, where he dashed his brains out against the wall. His extant writings are De Potestate Imperiali, and six books of letters on the acts of Frederick II., in bad Latin, but of much historical importance. Besides these, a sonnet and two canzone by him are among the earliest specimens of Italian literature.