1522

In 1522, a Sontaran scout ship crash-landed in China, severely damaging the ship's hyperspace transmitter. The Sontarans on board had to replace its quartz crystal, so they formed a partnership with the Abbot Hsiang and his assistant, Yueh. This alliance with Chinese monks was deemed strategic, because the Sontarans felt the monks could eventually lead them to the Chinese Emperor, whom they intended to assassinate. The emperor, as it turned out, was the only person who possessed the necessary quartz.
The Fourth Doctor and K9 intervened before the Sontaran plan could come to fruition. (COMIC: Dragon's Claw)