In 1214, when al-Tusi was 13 years old, Genghis Khan, who was the leader of the Mongols, turned away from his conquests in China and began his rapid advance towards the west.
Sa 1214, kapag al-Tusi ay 13 years old, Genghis Khan, na noon ay ang lider ng Mongols, nabuksan ang layo mula sa kanyang conquests sa Tsina at nagsimula sa kanyang mabilis na isulong sa kanluran.