The area of what is now Mongolia has been ruled by various nomadic empires, including the Xiongnu, the Xianbei, the Rouran, the Gökturks and others. The Mongol Empire was founded by Genghis Khan in 1206. After the collapse of the Yuan Dynasty, the Mongols returned to their earlier pattern of constant internal conflict and occasional raids on the Chinese borderlands. In the 16th and 17th centuries, Mongolia came under the influence of Tibetan Buddhism. At the end of the 17th century, most of Mongolia had been incorporated into the area ruled by the Qing Dynasty. During the collapse of the Qing Dynasty in 1911, Mongolia declared independence, but had to struggle until 1921 to firmly establish de facto independence from the Republic of China, and until 1945 to gain international recognition.
As a consequence, it came under strong Russian and Soviet influence; in 1924, the Mongolian People's Republic was declared, and Mongolian politics began to follow the same patterns as the Soviet politics of the time. After the breakdown of communist regimes in Eastern Europe in late 1989, Mongolia saw its own Democratic Revolution in early 1990, which led to a multi-party system, a new constitution in 1992, and transition to a market economy.
At 1,564,116 square kilometres (603,909 sq mi), Mongolia is the 19th largest and the most sparsely populated independent country in the world, with a population of around 2.9 million people. It is also