last imperial antipope, whose reign (May 1328 to August 1330) in Rome rivalled the pontificate of Pope John XXII at Avignon.

An assembly of priests and laymen in Rome under the influence of the Holy Roman emperor Louis IV the Bavarian, whom John had excommunicated, elected the Franciscan monk Pietro Rainalducci as the antipope Nicholas V. Having little support, Nicholas' cause proved fruitless. After John excommunicated him in April 1329, Nicholas, having been assured a pardon, renounced at Avignon his illegal claim to the papacy on Aug. 25, 1330. He remained in honourable imprisonment in the papal palace until his death.