Temüjin gradually built up a large army. He used it to conquer neighboring groups, including the Tatars. He unified those groups into a single Mongol nation. In 1206 the people named him Chinggis Khan, which means “universal ruler.” Chinggis Khan then set out to conquer other lands. First, he invaded northern China. In less than 10 years he and his generals took over most of China. Chinggis Khan next conquered the land that now makes up Turkmenistan and Uzbekistan. His generals raided Iran and Russia. Chinggis Khan began his last battle against China in 1226. He died in 1227. Mongols then controlled land from the China Sea to the European part of Russia. Chinggis Khan’s sons and grandsons expanded the Mongol Empire even more.