It was suggested that the motive of the murder was the brothers' rivalry in the affection of Donna Sancha, wife of Giuffre, the pope's youngest son, while there were yet darker hints at incestuous relations of Cesare and the duke with their sister Lucrezia.
He was attacked by assassins on the steps of St Peter's and badly wounded; attendants carried him to a cardinal's house, and, fearing poison, he was nursed only by his wife and Sancha, his sister-in-law.
But through the intervention of the Spanish ambassador he made peace with Naples in July 1493 and also with the Orsini; the peace was cemented by a marriage between the pope's son Giuffre and Dona Sancha, Ferdinand's grand-daughter.
Peter visited England several times, one of his nieces, Eleanor of Provence, being the wife of the English king Henry III., and another, Sancha, wife of Richard, earl of Cornwall.
Of Castile (1035-1065), by his marriage with Sancha, widow of the last king of Leon, was enabled to unite Leon and Castile in a single kingdom, with its capital at Burgos.
He married Sancha, sister and heiress of Bermudo, king of Leon.