<P> Genghis Khan also created a national seal, encouraged the use of a written alphabet in Mongolia, and exempted teachers, lawyers, and artists from taxes . </P> <P> The Mongols imported Central Asian Muslims to serve as administrators in China and sent Han Chinese and Khitans from China to serve as administrators over the Muslim population in Bukhara in Central Asia, thus using foreigners to curtail the power of the local peoples of both lands . The Mongols were tolerant of other religions, and rarely persecuted people on religious grounds . This was associated with their culture and progressive thought . Some historians of the 20th century thought this was a good military strategy: when Genghis was at war with Sultan Muhammad of Khwarezm, other Islamic leaders did not join the fight, as it was seen as a non-holy war between two individuals . </P> <P> At the time of Genghis Khan, virtually every religion had found Mongol converts, from Buddhism to Christianity, from Manichaeism to Islam . To avoid strife, Genghis Khan set up an institution that ensured complete religious freedom, though he himself was a tengrist or shamanist . Under his administration, all religious leaders were exempt from taxation and from public service . </P> <P> Initially there were few formal places of worship because of the nomadic lifestyle . However, under Ögedei (1186--1241), several building projects were undertaken in the Mongol capital . Along with palaces, Ögedei built houses of worship for the Buddhist, Muslim, Christian, and Taoist followers . The dominant religions at that time were Shamanism, Tengrism, and Buddhism, although Ögedei's wife was a Nestorian Christian . </P>

Describe the expansion of the mongol empire around asia and its collapse