War of Berke and Hulegu

Timeline

1. 1258–1261Baghdad and the Kipchak steppe · IraqIn 1258 Hulegu's Ilkhanid army captured Baghdad and executed the last Abbasid caliph al-Musta'sim, shocking the Islamic world. Berke, the Golden Horde khan who had already converted to Islam, was deeply outraged and relations deteriorated sharply. Meanwhile Hulegu detained Berke's envoys sent to Persia and refused to share tax revenues from Azerbaijan with the Golden Horde, sharply intensifying territorial and economic disputes between the two khanates and bringing war to the brink.
2. 1262along the Terek River · Terek River basinIn 1262 Berke Khan led the Golden Horde army south and fought Hulegu's Ilkhanid forces in the first major battle along the Terek River. The Golden Horde won the opening engagement, repelled the Ilkhanid vanguard, and at one point pursued into Shirvan (present-day Azerbaijan). However, after Hulegu personally led the main force to reinforce, the Golden Horde was forced to withdraw north of the Terek. This battle established the basic pattern of the war: evenly matched powers, with the Caucasus Mountains and the Terek River as the core strategic zone contested by both sides.
3. 1263–1264Sarai (capital of the Golden Horde) · lower VolgaAround 1263 Berke Khan established a formal diplomatic alliance with Mamluk Sultan Baybars I of Egypt, exchanging envoys through Byzantine territory. Bound by shared Islamic faith and aimed at countering the Ilkhanate, this alliance was an important event in medieval Islamic diplomacy. Baybars continuously pressured Hulegu from the direction of Syria, forcing the Ilkhanate to fight on two fronts and greatly easing the Golden Horde's military pressure in the Caucasus.
4. 1265the Caucasus and the northern frontier of the Ilkhanate · southern slopes of the CaucasusIn February 1265 Hulegu died in Azerbaijan and his son Abaqa succeeded as Ilkhan. Facing pressure from an internal transfer of power, Abaqa voluntarily reduced the intensity of offensives against the Golden Horde. The following year (1266), Berke Khan also died of illness near Tbilisi during a campaign. The successive deaths of both supreme commanders gradually quieted the fierce fighting on the Caucasus front. Although the two sides maintained a long-term hostile posture afterward, the phase of large-scale open warfare came to an end. The war ultimately produced no decisive territorial transfers, but firmly established the long-term strategic opposition between the Golden Horde and the Ilkhanate.