1216 Confirmation of the Dominican order. Death of Innocent. Cencio Savelli, Honorius III, elected.
1217 Honorius obliges Andrew of Hungary to undertake a crusade.
1220 Coronation of Frederick as emperor. He renews promises to go to the Holy Land.
1223 Congress at Ferentino. Frederick pledges himself to start within two years.
1225 Frederick obtains another delay. On account of trouble with the senate Honorius goes to Tivoli.
1227 Ugolino Conti, Gregory IX. He excommunicates Frederick, who makes an unsuccessful attempt to start for the Holy Land. Ezzelino da Romano drives the Guelfs out of Verona and Vicenza.
1228 Second excommunication of Frederick for starting without absolution. The pope sends his army into Apulia.
1229 The papal army ravages Apulia but Frederick hastens back from Syria to recover his territory. He is excommunicated a third time. Close of the Albigensian Crusade. Council of Toulouse forbids reading of Scripture by laymen and adopts severe measures for the suppression of heresy.
1230 The pope and Frederick are reconciled. Great flood in Rome.
1231 Negotiations are opened for the union of the Greek and Latin churches.