Pierre de la Vergne studied Canon law at the University of Montpellier.
[1] He was a disciple of Johannes Klenkok and was appointed cardinal deacon by Pope Gregory XI in 1371 taking the titular church Santa Maria in Via Lata.
[2] During the conflict about the Sachsenspiegel law book he handed the Decadicon - a written attack by Johannes Klenkok on the Sachsenspiegel - to Pope Gregory XI.
Gregory considered the attack and later issued the papal bull Salvator humani generis condemning 14 articles of the Sachsenspiegel on 8 April 1374.
[3] De la Vergne participated in the papal conclave 1378 during which Pope Urban VI was elected[4] and later in 1378 in the papal conclave that elected Antipope Clement VII.