Original: In the 16th and 17th centuries, Mongolia came under the influence of Tibetan Buddhism. At the end of the 17th century, most of Mongolia had been incorporated into the area ruled by the Qing Dynasty.
Simplified: After the 16th century, Mongolia came under the influence of Tibetan Buddhism and by the end of the 17th century, most of Mongolia had been incorporated into the area ruled by the Qing Dynasty.