Peter was born on July 20, 1369 at Ligny-en-Barrois to the royal Luxembourg-Ligny family — the nephew of King Wenceslaus IV of Bohemia and cousin of King Charles VI of France, the descendant of the medieval Luxembourg royal dynasty that had produced Emperor Charles IV of the Holy Roman Empire (Peter's great-uncle) and the Emperor Sigismund of the Holy Roman Empire (Peter's cousin, future emperor 1433).
Peter displayed extraordinary religious vocation from his earliest childhood. Educated at the Universities of Paris, he was appointed Bishop of Metz in 1384 at the age of 14 — and created Cardinal-Bishop of Metz by the Avignonese antipope Clement VII (the Avignonese antipope during the Great Western Schism 1378–1417) at the age of 15.
Peter undertook the cardinal-episcopal life at Avignon in extreme personal asceticism — refusing the cardinal-comforts and undertaking the personal poverty, personal fasting, and systematic charity to the poor. His contemporaries at Avignon reported the young cardinal's extreme personal disciplines (sleep on the floor, refusal of the cardinal-clothing, continuous prayer) as unprecedented in the medieval Catholic cardinal tradition.
Peter died at Avignon on July 2, 1387 at the age of just 17 years — after only three years of cardinal-episcopal service. His funeral at the Avignon Chapel of Saint-Michel attracted tens of thousands of faithful — producing the immediate pilgrim cult that would continue at his Avignon shrine.