text: This ruler annulled his daughter's marriage when her suitor could not pay an outrageous bride price consisting of 50,000 horses, 10,000 cows and camels, and 100,000 sheep.
full_question: This ruler annulled his daughter's marriage when her suitor could not pay an outrageous bride price consisting of 50,000 horses, 10,000 cows and camels, and 100,000 sheep. He erected six large stone panels across his empire to honor his six favorite horses. Whenever this ruler became sick, his wife would visit him carrying poison in her belt so she could commit suicide at a moment's notice. This husband of Empress Zhangsun was dissuaded from making sacrifices at a sacred mountain that shares his name by his minister Wei Zheng. This ruler launched an attack on the Xiyu States in the Tarim Basin after subjugating the Ashina dynasty in charge of the Eastern Turkic Khaganate, and also invaded the Goguryeo Dynasty of Korea. He came to power after ordering his men to assassinate his brothers at the Xuanwu Gate. This ruler succeeded Li Yuan, aka Emperor Gaozu, and proceeded to conquer much of Central Asia as far as present-day Kazakhstan. For 10 points, name this second emperor of the Tang Dynasty.
first_sentence: This ruler annulled his daughter's marriage when her suitor could not pay an outrageous bride price consisting of 50,000 horses, 10,000 cows and camels, and 100,000 sheep.
raw_answer: Tang Taizong [or Li Shimin; or T'ai-Tsung; prompt on "Li" or "Shimin"]