Catholic University of America (http://faculty.cua.edu/pennington/Crusades1070-1500.html)
Catholic University of America (http://faculty.cua.edu/pennington/Crusades1070-1500.html)

Events to the Sixth Crusader Initiative

1223 (July) CE - Philip II Augustus of France dies.
1224 CE - Emperor Frederick II founds University of Naples.
1225 (Nov) CE - Frederick II marries Yolanda (Queen of Jerusalem and daughter of John of Brienne).
1227 CE - Under pressure of Pope Gregory IX, Holy Roman Emperor Frederick II starts off on a Crusade, falls ill and cancels.
Beginning of the Sixth Crusade
1228 CE - Baldwin I crowned Emperor of the Latin Empire in Constantinople.
-Yoland bives birth to Conrad, son of Frederick II, but dies in childbirth.
(June 28) - Emperor Frederick II, now king of Jerusalem through marriage and death of Yolanda, sails east on crusade and arrives in Cyprus.
-An outbreak forces him to return, Pope Gregory IX does not accept his return and excommunicates Frederick II and a crusade against him is launched.
1229 (Feb) CE - Emperor Frederick II returns to defend himself against the armies of Pope Gregory IX
-Emperor Frederick II signs treaty with Sultan Malik Al-Kamil of Egypt and in return aquires control of Jerusalem, Nazareth, and Bethlehem from the Muslims.
-Pope Gregory IX does not support the treaty.
(March 18) - Emperor Frederich II crowns himself king of Jerusalem.
(May) - Emperor Frederich II returns home and regains control of his lands from Pope Gregory IX.
(Aug) - Emperor Frederich II and Pope Gregory IX arrive at a peace treaty. Thus ending the Sixth Crusade.