In 1507 the Inquisition, instigated by Ferdinand V., undertook to prosecute and arrest Cæsar Borgia, Duke de Valentinois, and brother-in-law to John d'Albret, King of Navarre. It is most probable that this prince would have been taken, if he had not been killed in the same year before Viana, not far from Logroño, by the governor of a fortress, Juan Garces de los Fayos. Cæsar Borgia was the natural son of Don Rodrigo de Borgia (afterwards raised to the papal see, by the name of Alexander VI.), and the famous _Vanoci_. He had been a cardinal, but, in 1499, his father, in compliance with the request of Louis XII. King of France, who adopted him, granted him dispensations to marry the sister of the King of Navarre; he then obtained the titles and estates of the dukedom of Valentinois. A short time after the death of Cæsar Borgia's father, in 1503, he was arrested at Naples, by the order of Gonzalo de Cordova, viceroy of that monarchy, on the pretence that he disturbed the tranquillity of the kingdom. He was taken to Spain, and confined in the Castle of Medina del Campo, from whence he made his escape, and fled to Navarre. Ferdinand, finding that his niece, the Queen of Navarre, would not give up this prince to him, resolved to secure him by means of the Inquisition. It has been already stated that the inquisitors did not prosecute the memory of Charles V.; but in 1565, they were concerned in the proceedings against Jane d'Albret, the hereditary Queen of Navarre, and against her son, Henry de Bourbon, afterwards Henry IV. of France, and his sister, Margaret de Bourbon Albret, who married the sovereign Duke of Bar. The holy office, however, did not take an active part in this affair. After Ferdinand V. had taken possession of the five districts of the kingdom of Navarre, called _Merindades_, he refused to recognise either Jane or Henry de Bourbon as sovereigns of Navarre. These princes were deprived of all their dominions, except the sixth _Merindade_ of Navarre, by a papal bull in 1512; the Court of Rome also refused to grant them the title of Kings of Navarre until the year 1561. The first to whom it was given was Anthony de Bourbon.