Innocent IV

Innocent IV d. 1254, pope (1243-54), a Genoese named Sinibaldo Fieschi, a distinguished jurist who studied and later taught law at the Univ. of Bologna; successor of Celestine IV. He was of a noble family. Although he had been regarded as sympathetic to the empire, once pope he quickly took up the papal struggle with Frederick II and the Hohenstaufen . After a futile treaty he felt unsafe in Rome and fled to Lyons, where he convened the Council of Lyons (1245; see Lyons, First Council of ). Frederick was condemned again and declared deposed, and Innocent supported Henry Raspe and, later, William II of Holland as pretenders to the imperium. He also tried to get an English or French prince to take Sicily as a fief, but Frederick was too strong. Frederick died as the pope was opening a crusade against him (1250). Innocent did not spare the other Hohenstaufen, Conrad IV and Manfred , but after finding them invincible in Sicily, he recognized Conradin as king of Sicily. Innocent was almost wholly occupied with his quarrel with the Hohenstaufen, and the taxes he levied to continue it made him unpopular with clergy and laity alike. He was succeeded by Alexander IV.

Innocent IV (d. 1254), Pope from 1243. He was the most outstanding canon lawyer ever to become Pope, and he wrote a major commentary on the Decretals, known as the ‘Apparatus’. Having tried unsuccessfully to resolve the dispute with Frederick II which he had inherited, at the Council of Lyons in 1245 he excommunicated and deposed him, and continued the struggle against his son. Under the pressure of financial needs he extended the system of provisions, and he authorized the use of torture by the Inquisition.