Shamanism and Buddhism co-existed in Mongolian from the times of Chingis Khan. Khubilai Khan (grand son of Chingis) made Buddhism the state religion of the Yuan Empire. During the 16th century, Tibetan Lamaism came to Mongolia and numerous monasteries were built from the 17th century onwards, when Mongolia developed into a theocracy with strong links with Tibet. In the 1930’s and 40s,following the Stalinist system, more than 740 temples and monasteries were destroyed. People couldnt express their feelings openly during that time. The 3 major Buddhist centers in Mongolia are Gandan, Erdene Zuu and Amarbayasgalant monasteries which built by the first theocrat ruler Ondor Gegeen Zanabazar.