The Fourth Lateran Council ranks among the most important ecumenical councils in the history of Christianity. In 1213 Pope Innocent III called on the religious and secular leaders of Christendom to meet at the Lateran complex in Rome in November 1215. The main aims of the council were the reform of the church and the recovery of the Holy Land. More than 400 bishops, archbishops, patriarchs, and cardinals attended the council, as well as a multitude of representatives of cathedral chapters and monasteries. Most of the major secular governments of Christendom were represented, including those of the cities of northern Italy.
Among its political decisions, the council approved the candidacy of Frederick (II), king of Sicily, as Holy Roman Emperor and awarded most of the lands of Count Raymond VI of Toulouse to Simon of Montfort, leader of the Albigensian Crusade (1209-1229). It approved seventy constitutions, the first of which was a creed of the Christian faith that explicitly countered the doctrines of the major heresies of the day. The remaining constitutions can be grouped roughly under six headings: heretics and Jews, organizational and judicial reforms, marriage law, clerical appointments and support, reforms of the clergy, and reforms of the laity. Notable among these provisions were requirements that Jews were to wear distinctive clothing, provincial councils of bishops were to meet triennially to consider necessary reforms (with a similar requirement for monastic orders), and all Christians were to confess their sins annually and receive the Eucharist at Easter. The council also forbade clergy from participating in trials by ordeal, thereby hastening the end of that form of judicial procedure. Finally, it approved Innocent’s letter setting forth detailed plans for the Fifth Crusade (1217-1221), which the pope had first announced in 1213.
It is difficult to determine how effective the council’s actions were. Many of the directives were widely neglected, and there were considerable variations in time and place. It does seem likely that some of the constitutions had enduring influence, as is evidenced by the widespread practice among modern Catholics of observing the “Easter duty.”