Innocent III (1160 or 1161 – 16 July 1216) is Pope from 8 January 1198 until his death.

His birth name is Lotario dei Conti di Segni, sometimes anglicized to Lothar of Segni.

Pope Innocent is one of the most powerful and influential popes.

He exerts a wide influence over the Christian regimes of Europe, claiming supremacy over all of Europe's kings.

Pope Innocent is central in supporting the Catholic Church's reforms of ecclesiastical affairs through his decretals and the Fourth Lateran Council.

This results in a considerable refinement of the Western canon law.

Pope Innocent is notable for using interdict and other censures to compel princes to obey his decisions, although these measures are not uniformly successful.

Innocent calls for Christian crusades against Muslims in Spain and the Holy Land and against heretics in southern France (Albigensian Crusade).

One of Pope Innocent's most critical decisions is organizing the Fourth Crusade.

Originally intended to attack Islam through Egypt, a series of unforeseen circumstances lead the crusaders to Constantinople, where they ultimately attack and sack the city (1204).

Innocent reluctantly accepts this result, seeing it as the will of God to reunite the Greek and Latin churches, but it poisons relations between the two churches.