During the eleventh century, the so-called renaissance continued with enormous translation efforts and translators travelling between Tibet and India along existing trade routes. Drapa Ngonshe, the treasure revealer credited with producing the Four Tantras, the root texts of Tibet’s medical tradition, was born in 1012. The monastery of Tangpoche was founded in 1017 by the Eastern Vinaya Monks, the men who preserved monastic ordination following the collapse of the state monasteries. The translator Marpa taught Mahāmudrā to Milarepa, the great Tibetan saint, who was born in 1040. The Bengali monk Atisha arrived in Guge in 1042, traveled to central Tibet in 1045, and spent thirteen years teaching in Ngari, U, and Tsang. In 1040, Chetsun Sherab Jungne of the Che clan founded Zhalu Monastery. Machik Labdron, the codifier of Chod practice, was born in 1055. Reting Monastery, the great Kadampa monastery to the northeast of Lhasa, was founded by Atisha's student Dromtonpa in 1057. Sakya Monastery was founded by Khon Khonchok Gyelpo in 1073. The Tsongkha kingdom in the northeast of Tibet fell to the Song Dynasty in 1099.