Question: Who is Emperor Ruizong Of Tang's paternal grandmother?
Sentence (from "Emperor Gaozong of Tang"): During the first part of his reign, Tang territorial gains, which started with his father Emperor Taizong, continued, including the conquest of Baekje, Goguryeo, and the Western Turkic Khaganate, but throughout the 670s, much of those gains were lost to the Tibetan Empire, Silla, Khitan, and Balhae.
Relevant evidence: No