Innocent IV was a pope who served from 1243 to 1254. Born as Sinibaldo Fieschi, he was known for his efforts to strengthen the authority of the papacy and to address issues within the Catholic Church. He played a significant role in the political landscape of Europe during his papacy, particularly in his dealings with the Holy Roman Empire. One of his notable actions was the issuance of the bull Ad extirpanda, which allowed for the use of torture in the investigation of heresy. Innocent IV also supported the Franciscan and Dominican orders, promoting their missions and influence throughout Europe. His reign was marked by both religious and political challenges.