The well-mounted army of Andrew II of…

The Khitan ruler Yelü Liuge is expelled as a result of an internal strife in the so-called Liao kingdom of the Khitans, or Eastern Xia, and seeks support from Genghis Khan.

The Khitans suffer a counterattack from Jin and flee to Goryeo without permission from the Mongols.

Puxian Wannu capitulates to Muqali's army and sends his son Tege (Tiěgē) as a hostage in 1216.

However, he revolts soon after that and flees to an island while the Mongol army invades Liaoxi and Liaodong.

Afonso II of Portugal captures Alcácer do Sal from the Moors in 1217.

Peter II of Courtenay, the son of Peter I of Courtenay (d. 1183) and a grandson of the French king Louis VI by his second Queen consort Adélaide de Maurienne, had obtained the counties of Auxerre and Tonnerre by his first marriage.

He had later married Yolande, sister of Latin emperors Baudouin and Henri of Flanders, who brought him the marquessate of Nevers.

Peter had accompanied his cousin, King Philip II, on the crusade of 1190, fought against the Albigenses in southern France, and was present at the Battle of Bouvines in 1214.

Chosen successor to Henry of Flanders when the emperor dies without sons, Peter is consecrated emperor in the Church of San Lorenzo Fuori le Mura, Rome, by Pope Honorius III on April 9, 1217.

Accompanied by an army and a papal legate, Peter subsequently embarks at Brindisi on ships furnished by the Venetians.

King Inge of Norway falls ill in Nidaros in 1217 and appoints his younger half-brother, Skule Bårdsson, earl and leader of the army.

Inge dies on April 23 and is buried in Nidaros Cathedral.

He is succeeded as king by the thirteen-year-old Haakon Haakonsson, an illegitimate grandson of king Sverre, who had been raised at the courts of king Inge and earl Haakon since they became aware of his existence in 1206.

Skule will continue as earl and de facto ruler for the next few years.

King Andrew II of Hungary had married Yolanda, the niece of Henry I, the Emperor of Constantinople, in February 1215.

When the Emperor Henry I died on July 11, 1216, Andrew had planned to acquire the imperial throne, but the barons of the Latin Empire had proclaimed his father-in-law, Peter of Courtenay, their emperor.

Andrew has decided nonetheless to fulfill his father's oath and makes preparations for a Crusade to the Holy Land in 1217, one of several foreign misadventures that will prove costly to Hungary.

William Marshal is declared the protector of the nine-year-old Henry III in the aftermath of John's death.

The civil war continues until royalist victories at the battles of Lincoln and …

…Dover in 1217.

Louis, on landing in England the previous year, had captured all of the Cinque Ports in the southeast, except for Dover, where Hubert de Burgh has stubbornly held out against a siege of many months.

Peter II of Courtenay, failing in his attempt to conquer Durazzo from Theodore Doukas for his Venetian creditors, sets out overland toward Constantinople but …

…is seized in the mountains near Elbasan and imprisoned by Theodore, who most likely executes him after an imprisonment of at least two years.