1211

Events

June 17 - Battle of Antioch on the Meander: Seljuk forces led by Sultan Kaykhusraw I are initially victorious with the Latin mercenary cavalry bearing the brunt of the casualties due to their flanking charge; exhausted by the effort in their attack, the Latin army under Emperor Theodore I Laskaris is struck in the flank and rear by the Seljuk forces. However, the Seljuks stop the fight in order to plunder the Latin camp – which allows Theodore's forces to rally and counter-attack the now disorganized Turks. Meanwhile, Kaykhusraw seeks out Theodore and engages him in single combat, but he is unhorsed and beheaded. The Seljuks are routed and the former Byzantine emperor Alexios III Angelos, Theodore's father-in-law, is captured and imprisoned, ending his days in enforced monastic seclusion.
October 15 - Battle of the Rhyndacus: Latin emperor Henry of Flanders lands with an expeditionary force at Pegai, and marches eastwards to the Rhyndacus River. The Byzantine army under Theodore I prepare an ambush, but Henry assaults his positions along the river and defeats the Byzantine army in a day-long battle. Henry marches unopposed through the remaining Byzantine lands, reaching south as far as Nymphaion.

Spring - Genghis Khan summons his Mongol chieftains, and prepares to wage war against the Jurchen-led Jin dynasty in northern China. He advances across the Gobi Desert with a massive army of 100,000 warriors with 300,000 horses, strung out in perhaps 10–20 groups of 5,000–10,000 men each, each with camel-drawn carts, and all linked by fast-moving messengers. Meanwhile, the Jin Government mobilizes an army of 800,000 men, most of which are untrained peasants with low morale, and some 150,000 highly-trained cavalry. This vast army, however, is spread across the Great Wall, and garrisoned separate fortresses.
Battle of Yehuling: Genghis Khan bypasses the Great Wall with little opposition, and splits his forces into two armies. The main army is led by himself, and the other army is taken by his son Ögedei to attack the city of Datong. Genghis heads for the strategic Juyong Pass – which leads down to the capital of Zhongdu, but along the way he is halted at the pass of Yehuling where the bulk of the Jin army awaits him. Between March and October, the battle is fought in three stages, after Genghis has defeated the Jin forces, he begins raiding the countryside before he withdraws for the winter.

Spring - Albigensian Crusade: Crusader forces led by Simon de Montfort conquer Toulouse and besiege Lavaur in southern France. On May 3, the city is retaken; on orders of Montfort the senior knights are hanged and some 400 Cathars are burned alive.
March 26 - King Sancho I of Portugal dies after a 25-year reign at Coimbra. He is succeeded by his son Afonso II as ruler of Portugal. During his reign, he designs the first set of Portuguese written laws.
Livonian Crusade: Battles of Viljandi and Turaida - The Crusaders fail to conquer the Viljandi stronghold, but manage to baptize Sakala and Ugandi counties.
September - The 16-year-old Frederick II is elected in absentia as German king by rebellious nobleman at the Diet of Nuremberg.

Summer - King John of England campaigns in Wales against Llywelyn the Great, prince of Gwynedd. In July, after the Welsh uprising, John and Llywelyn reach an agreement and a peace treaty is signed.
June - Papal legate Pandulf Verraccio arrives in Northampton to serve John with his excommunication ordered by Innocent III. For John this is a serious blow to his ability to rule the country.
John sends a gift of herrings to nunneries in almost every shire, despite his status as an excommunicant.
The Papal Interdict of 1208 laid by Innocent III remains in force after John refuses to accept the pope's appointee.

June - Shams ud-Din Iltutmish, son-in-law of the former Sultan Qutb al-Din Aibak, becomes ruler of the Delhi Sultanate and quells the Hindu rebellions in India.

April 21 - Santiago de Compostela Cathedral is consecrated, in the presence of King Alfonso IX of León.
Archbishop Aubrey lays the first stone of the chevet of Reims Cathedral.