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Nicholas V, born Pietro Rainalducci (died October 16, 1333) was an antipope in Italy from May 12, 1328 to July 25, 1330 during the pontificate of Pope John XXII (1316–34) at Avignon.
On February 19, 1329 Nicholas V presided at a bizarre ceremony in the Duomo of Pisa, at which a straw puppet representing Pope John XXII and dressed in pontifical robes was formally condemned, degraded, and handed over to the secular arm.
Nicholas V was excommunicated by John XXII in April 1329, and sought refuge with Count Boniface of Donoratico near Piombino.