In 1211, after the conquest of Western Xia, Genghis Khan, the founder of the Mongol Empire mobilized an army to conquer the Jin dynasty, which controlled much of North China including Manchuria.

The Khitans under Yelü Liuge declared their allegiance to Genghis Khan and established the nominally autonomous Eastern Liao in Manchuria in 1213.

Some time after 1234 Ögedei also subdued the Water Tatars in the northern part of the region and began to receive falcons, harems and furs as taxation.

Rather, the Mongols developed a fluid system of governance in Manchuria designed to extract economic and military resources while maintaining local stability.

As members of the Northeast Asian elite, the Korean Hong family dominated the Liaoyang Branch Secretariat during the late 13th and the early 14th centuries.

When Qadan resumed his revolt and attacked the Goryeo capital of Kaesong, the Yuan Zhongshu Sheng specifically appointed Hong Dagu to pacify the region east of the Liao River and granted him wide latitude to accomplish this task.

[2] Kublai Khan's efforts to restore order in the region after the revolts by Nayan and Qadan reflect the complex nature of Manchuria under the Mongols.

Kublai stove to balance the interests of the Goryeo throne, local Mongol nobles, leaders of the Korean community in Manchuria, and his own court to restore order in the northeast.

However, the Yuan government still felt the need to periodically dispatch special emissaries to assist officials in Manchuria in tours of inspections.

A military institution named the Zhengdong Marshal Office (征東元帥府) was established to govern the region surrounding the lower course of the Amur River and the Sakhalin.