Year 1211 (MCCXI) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar. Events By place Byzantine Empire June 17 – Battle of Antioch on the Meander: Seljuk forces led by Sultan Kaykhusraw I are initially victorious with the Latin mercenary cavalry (some 800 men) 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 (some 3,000 men) at Pegai, and marches eastwards to the Rhyndacus River. The Byzantine army (much larger in force overall) 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. Mongol Empire 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 (60,000 men) 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 (Young Badger's Mouth) – which lead down to the capital of Zhongdu (modern-day Beijing), but along the way he is halted