The Mongolian Empire was one of the largest and most influential empires in history, founded by Genghis Khan in the early 13th century. At its peak, the Mongolian Empire stretched from Eastern Europe to East Asia, making it the largest contiguous land empire in the world. Genghis Khan's military tactics and leadership skills allowed the Mongols to conquer vast territories and establish a powerful empire. 

The Mongolian Empire facilitated cultural exchange and trade along the Silk Road, connecting the East and West. The empire was known for its administrative innovations, religious tolerance, and promotion of meritocracy. After Genghis Khan's death, the empire was divided into four khanates, each ruled by one of his descendants. The Mongolian Empire had a lasting impact on world history, shaping the development of trade, warfare, and diplomacy in Eurasia.

Mongols occupied Baghdad on January 29, 1258.

Before the invasion, he repeatedly sent letters to the caliph calling on him to surrender, and demanded that he come in person or send his viceroy, but "Millions of horses and men are ready to go to war. They only await my orders. If you provoke me to anger, we will even the waters of the sea."  "I will dry up," he answered proudly, and refused to obey, and the war began.