Mongol invasion of Europe: Mongol forces led by Batu Khan and Subutai defeated the army of King Béla IV at the Battle of Mohi near the river Sajó, a key victory in their first invasion of Hungary.

From the 1220s to the 1240s, the Mongols conquered the Turkic states of Volga Bulgaria, Cumania and Iranian state of Alania, and various principalities in Eastern Europe. Following this, they began their invasion into Central Europe by launching a two-pronged invasion of then-fragmented Poland, culminating in the Battle of Legnica, and the Kingdom of Hungary, culminating in the Battle of Mohi. Invasions were also launched into the Caucasus against the Kingdom of Georgia, the Chechens, the Ingush, and Circassia though they failed to fully subjugate the latter. More invasions were launched in Southeast Europe against Bulgaria, Croatia, and the Latin Empire. The operations were planned by General Subutai (1175–1248) and commanded by Batu Khan and Kadan, two grandsons of Genghis Khan. Their conquests integrated much of Eastern European territory into the empire of the Golden Horde. Warring European princes realized they had to cooperate in the face of a Mongol invasion, so local wars and conflicts were suspended in parts of central Europe, only to be resumed after the Mongols had withdrawn. After the initial invasions, subsequent raids and punitive expeditions continued into the late 13th century.

Mongols are an East Asian ethnic group native to Mongolia and China, as well as the republics of Buryatia and Kalmykia in Russia. The Mongols are the principal member of the large family of Mongolic peoples. The Oirats and the Buryats are classified either as distinct ethno-linguistic groups or as subgroups of Mongols.

Batu Khan was a Mongol ruler and founder of the Golden Horde, a constituent of the Mongol Empire established after Genghis Khan's demise. Batu was a son of Jochi, thus a grandson of Genghis Khan. His ulus ruled over the Kievan Rus', Volga Bulgaria, Cumania, and the Caucasus for around 250 years.

Subutai was a Mongol general and the primary military strategist of Genghis Khan and Ögedei Khan. He ultimately directed more than 20 campaigns, during which he conquered more territory than any other commander in history as part of the expansion of the Mongol Empire, the largest contiguous empire in human history. He often gained victory by means of sophisticated strategies and routinely coordinated movements of armies that operated hundreds of kilometers apart from each other. Subutai is regarded as one of the greatest military commanders in history, and the single greatest in Mongolian history. He was instrumental in the conquests of Genghis Khan and Ögedei Khan.