After occupying the episcopal sees of Therouanne and Cambrai, he attained to the cardinalate at an early age.
By the promotion to the cardinalate of such men as Contarini, Caraffa, Pole and Morone, and the appointment of a commission to report upon existing evils and their remedy, the way was opened for reform; while by the introduction of the Inquisition into Italy (1542), the establishment of the censorship and the Index (1543), and the approval of the Society of Jesus (1540), most efficient agencies were set on foot for combating heresy.
His services were rewarded by a cardinalate and the archbishopric of Ferrara.
He was degraded from the cardinalate by Leo X.
In 1514, and reaped his reward in the bishoprics of Lincoln and Tournai, the archbishopric of York, which was conferred on him by papal bull in September, and the cardinalate which he had sent Polydore Vergil to beg from Leo X.
His nominations to the cardinalate were not happy.
Returning to England to raise money for a fresh crusade, he was received with great state in London; but his acceptance of the cardinalate had weakened his position and Gloucester refused to recognize his legatine commission.
In a few years Leo had made peace with Austria, pacified Switzerland and Belgium, opened up negotiations with Russia; while his elevation of Newman to the cardinalate (1879) made a great impression in Great Britain.
It is estimated that this cardinalate cost France about eight million francs.
Frederick, who had been raised to the cardinalate by Leo IX., acted for some time as papal legate at Constantinople, and was with Leo in his unlucky expedition against the Normans.