Sister of Piroz III and daughter of Yazdegerd III and wife of Li Yuan

[ Pirooz, scared and was awaiting the help of Chinese armies. He had written to his sister who was the wife of the Chinese emperor. ]

ref : In 651 A.D., the Persian king Yazdgerd III was captured and beheaded by Arab invaders in what is today's Turkmenistan. His son, Pirooz survived and fled east to China. Here's an account from Chinese historians.

[... In 751 A.D., the Chinese lost a decisive battle to the Arabs at Talas (now in Uzbekistan), and they retreated from their colonies in Central Asia. All the garrisons shut down, and the armies fled back into China. Many Persians and Sogdians followed the Chinese back into China and abandoned their homes in Central Asia in wake of the Muslim Arabic invasions. Some Sogdians came as widows who then married Chinese soldiers along with their orphaned children.

Narseh recounts in his diary of how his father set foot in China around the 660s A.D. Pirooz was only a little boy when the Arabs beheaded his father.

Pirooz, scared and was awaiting the help of Chinese armies. He had written to his sister who was the wife of the Chinese emperor.

With the Arab armies in sight, he waited no longer. They decided to cross the Pamirs. Their families along with other noble Persian clans and the soldiers crossed the treacherous snowy mountains. Many of the imperial treasures were either abandoned or lost. Recently, Chinese research teams recovered some of the lost items. They are now housed in various museums in Beijing or Taiwan.]

ref: http://www.iranchamber.com/history/articles/pirooz_in_china.php