In the early 16th century, Dayan Khan and his khatun Mandukhai reunited the entire Mongol nation under the Genghisids. In the mid-16th century, Altan Khan of the Tümed, a grandson of Dayan Khan – but not a hereditary or legitimate Khan – became powerful. He founded Hohhot in 1557. After he met with the Dalai Lama in 1578, he ordered the introduction of Tibetan Buddhism to Mongolia. (It was the second time this had occurred.) Abtai Khan of the Khalkha converted to Buddhism and founded the Erdene Zuu monastery in 1585. His grandson Zanabazar became the first Jebtsundamba Khutughtu in 1640. Following the leaders, the entire Mongolian population embraced Buddhism. Each family kept scriptures and Buddha statues on an altar at the north side of their ger (yurt). Mongolian nobles donated land, money and herders to the monasteries. As was typical in states with established religions, the top religious institutions, the monasteries, wielded significant temporal power in addition to spiritual power.