Year 1223 (MCCXXIII) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar. Events By place Mongol Empire Spring – The Polovtsian army assembles on the Terek River lowlands and are joined by Alan, Circassian, and Don Kipchak/Cuman forces. The Mongol army crosses the Caucasus Mountains, but is trapped in the narrow mountain passes. The Mongol generals Subutai and Jebe (the Arrow) send an embassy to the Polovtsians and convince them to break their alliance with the Caucasian peoples. The Mongol cavalry invades the Caucasus region and devastates the local villages, seizing slaves, cattle and horses. The Mongol army invades Polovtsian territory and defeats the Polovtsians in a great battle near the Don River. Several Polovtsian leaders are killed – while the remainder flees westwards, across the Dnieper River, to seek support by various Russian princes. Steppe lands east of the Dnieper fall under Mongol control, Subutai and Jebe raise the wealthy city of Astrakhan on the Volga River. Subutai now parts his forces, he moves south to the Crimea (or Tauric Peninsula), while Jebe travels towards the Dnieper. Mongol forces capture the nominally Genoese trading outpost of Sudak, probably with the tacit approval of neighbouring rival Venetian outposts in the Crimea. Subutai promises to destroy any non-Venetian colonies in the area. In return, the Venetians provide Subutai with information about the kingdoms in Eastern Europe. Meanwhile, Köten Khan, Cuman/Kipchak chieftain of the Polovtsians, convinces Prince Mstislav Mstislavich of Galicia to form an alliance, and informs him of his plight against the Mongols. February – A council of Russian princes summons at Kiev; several princes are convinced by Köten Khan to assemble an allied army to drive the Mongols back. During the first half of March, Russian princes return to their principalities and begin to raise forces for the forthcoming campaign. The alliance has a combined force of some 60,000 men, mainly cavalry. Subutai unites his army with Jebe, and sends ambassadors to the Kievan Rus' princes, to tell them to stay out of the conflict as it didn't involve them. April – The Russian princes lead their separate armies from different parts of Russia, to assemble 60 kilometres downriver from Kiev. There are three main groups of princes taking part in the campaign; the Kievan army is represented by Grand Prince Mstislav Romanovich (the Old). The second group are the Chernigov and