Buyeo entered into formal diplomatic relations with the Eastern Han dynasty by the mid-1st century AD as an important ally of that empire to check the Xianbei and Goguryeo threats.

[12][13] There are no scholarly consensus on the classification of the languages spoken by the Puyo, with theories including Japonic,[14] Amuric[15] and a separate branch of macro-Tungusic.

After its foundation, the son of heaven (Hae Mo-su Korean: 해모수; Hanja: 解慕漱) brought the royal court to his new palace, and he was proclaimed to be King.

[25] In particular was the state of Yan which introduced iron technology to Manchuria and the Korean peninsula after its conquest of Liaodong in the early third century BC.

[28] This was advantageous to the Han as an ally in the northeast would curb the threats of the Xianbei in western Manchuria and eastern Mongolia and Goguryeo in the Liaodong region and the northern Korean peninsula.

[29] During a period of turmoil in China's northeast, Buyeo attacked some of Eastern Han's holdings in 111, but relations were mended in 120 and thus a military alliance was arranged.

[27] In the early 3rd century, Gongsun Du, a Chinese warlord in Liaodong, supported Buyeo to counter Xianbei in the north and Goguryeo in the east.

Part of the expeditionary force led by Wang Qi (Korean: 왕기; Hanja: 王頎), the Grand Administrator of the Xuantu Commandery, pursued the Guguryeo court eastward through Okjeo and into the lands of the Yilou.

[34] Considering its friendly relationship with the Jin Dynasty, Emperor Wu helped King Uira (依羅) revive Buyeo.

[39] Many ancient historical records indicate the "Jolbon Buyeo" (Korean: 졸본부여; Hanja: 卒本夫餘), apparently referring to the incipient Goguryeo or its capital city.

[40][page range too broad] According to Chapter 30 "Description of the Eastern Archerians, Dongyi" in the Chinese Records of the Three Kingdoms (3rd century), the Buyeo were agricultural people who occupied the northeastern lands in Manchuria (North-East China) beyond the great walls.

Their people are coarsely big; by temperament strong and brave, assiduous and generous, they are not prone to brigandage... For their dress within their state they favor white; they have large sleeves, gowns, and trousers, and on their feet they wear leather sandals...

The people of their state are good at raising domestic animals; they also produce famous horses, red jade, sables, and beautiful pearls... For weapons they have bows, arrows, knives, and shields; each household has its own armorer.

[46] In the 1930s, Chinese historian Jin Yufu (金毓黻) developed a linear model of descent for the people of Manchuria and northern Korea, from the kingdoms of Buyeo, Goguryeo, and Baekje, to the modern Korean nationality.