That was in year 616 Hijrah according to Al-Imaam Ibn Katheer in Al-Bid‚yah wa An-Nih‚yah
In the year in question, the Tartars, accompanied by their King, Genghis khan, left their country and crossed over River Jihun (Ceyhan River); they were staying at Mountain Tamghaj in China. They spoke a different language from that spoken by the other Tartars; they were the most courageous and persevering of the Tartars at wars.
The reason for their entering River Ceyhan was because Genghis Khan had sent some traders to Khwarezm Shah's city with a lot of money to purchase clothes to be worn. His deputy among the team of traders wrote to the Sultan of Khwarezm Shah to inform of the huge amount of money they had with them; the Sultan sent some people to assassinate them and seized the money with them, that which was done. When Genghis Khan got this news, he was ferociously furious, and he promptly sent a severely threatening message to the Khwarezm Shah; Khwarezm Shah had not done well. After the threatening message, Khwarezm plotted an attack against them. And then they were busy and engaged with the killing of Kashlar Khan, so Khwarezm Shah pillaged their belongings, captured their women and the little children.
They staged a reprisal attack and engaged them in a severe battle for four days, the like which had not been heard of in the history. Those were defending their harems while the Muslims were defending their souls; they were dead sure that if they were to turn back, the Tartars would annihilate them. Each of the two warring factions lost a great number of people so much that horses were skating in the pool of blood. Around twenty thousand Muslims were killed in the war while the Tartars lost multiple of that on their side. Each of the parties then stayed apart after which they both returned to their countries. Khwarezm Shah, together with his people, moved to Bukhara and Samarqand; they fortified the places and left a lot of warriors behind; and then Khwarezm Shah returned to his country to empower this great number of soldiers.
The Tartars marched forth to Bukhara, which had already been ready with around twenty thousand soldiers; Genghis Khan rounded up the place for three days, and its residents sought that he did them no harm that which he consented to. Then he entered Bukhara and treated the residents nicely, with some sinister motives. He was denied an access to the fortress, so he besieged it. The guards of the fortress were made to flood its trench. The Tartars destroyed the pulpits and the pages of the Qur'‚n and flooded the trench with them. They forcibly conquered it in ten days and killed the guards of the fortress.
They returned to the city, usurped the wealth of the traders, distributed it to the soldiers and killed a great number of people whose number could not be enumerated by anybody except All‚h Ė the Mighty and Sublime. They captured the little children and the women, and raped the women in the presence of their men. Some of the men fought in the defence of their female relatives until they were killed; some of them were taken as captives of war and subjected to various kinds of tortures. Cries and rackets of women, little children and men permeated the whole city.
After all this, the Tartars razed down the abodes of people, Institutes and the mosques in Bukhara after which they vacated the city and headed to Samarqand.
TARTARS' CAPTURE OF BAGHDADAD
TARTARS' CAPTURE OF DAMASCUS
END OF THE TARTARS