Pope Innocent III, having since 1208 planned a crusade in order to destroy the Ayyubid Empire and to recapture Jerusalem, had in April 1213 issued the papal bull Quia maior, calling all of Christendom to join a new crusade.
This had been followed in 1215 by another papal bull, the Ad Liberandam.
Innocent had in 1215 summoned the Fourth Lateran Council, where, along with the Latin Patriarch of Jerusalem, Raoul of Merencourt, he had discussed the recovery of the Holy Land, among other church business.
Pope Innocent wants it to be led by the papacy, as the First Crusade should have been, in order to avoid the mistakes of the Fourth Crusade, which had been taken over by the Venetians.
Innocent plans for the crusaders to meet in 1216 at Brindisi and to ensure that the crusaders will have ships and weapons prohibits trade with the Muslims.
Every crusader will receive an indulgence, including those who simply help pay the expenses of a crusader, but do not go on crusade themselves.
The message of the crusade had been preached in France by Robert of Courçon; however, unlike other Crusades, not many French knights have joined, as they are already fighting the Albigensian Crusade against the heretical Cathar sect in southern France.
Oliver of Cologne had preached the crusade in Germany, and King Frederick II of Sicily, a Hohenstaufen and grandson of Frederick I Barbarossa, twice crowned king of the Germans, had in 1215 attempted to join.
Frederick was the last monarch Innocent wanted to join the movement, as he had challenged the Papacy (and would do so in the years to come).
Innocent dies, however, in 1216.
Honorius III, who succeeds Innocent on July 28, immediately activates Innocent's plan to restore the kingdom of Jerusalem, organizing crusading armies led by King Andrew II of Hungary and duke Leopold VI of Austria.