Jonathan Fenby "China's Imperial Dynasties 1600 BC - AD 1912" Metro Books, New York
Tang Dynasty. The Founders
p.105
Turkish roots
"Seeking to avoid the frequent succession disputes, Taizong named one of his 14 sons as his heir early in his reign. But the young man had a homosexual affair that horrified his father, who ordered his lover to be killed. After that, the prince developed a fixation with the dynasty's Turkic roots, insisting on speaking Turkish rather than Chinese, wearing Central Asian clothes, living in a tent and stealing sheep which he cooked over a camp fire. He also plotted against a brother whom Taizong favoured for a while. In the end, both men were disgraced and exiled, and a younger son, Li Zhi, became the official heir..."
http://www.amazon.com/Chinas-Imperial-Dyna...575&sr=1-21