Jangsu of Goguryeo

Jangsu, the twentieth monarch of Goguryeo, the northernmost of the Three Kingdoms of Korea, has reigned from the age of nineteen reigned over the peak of Goguryeo's power, building on the territorial expansion of his father, King Gwanggaeto the Great.

Now entering his thirties, he has dedicated much of his efforts towards stabilizing a kingdom that had experienced great and sudden growth, a direct result of his father's conquests.

Jangsu has built a magnificent tomb for his father, and along with it an imposing four-meter tall tombstone carved from a single mass of granite and engraved with his father's accomplishments (now known as the Gwanggaeto Stele).

Of such imposing dimensions is the tomb and its grounds that it requires three hundred and thirty people to tend it at all times, called from different regions and tribal backgrounds to guard and clean the tomb in perpetuity: a demonstration of the effective consolidation of the Goguryeo kingdom and monarch's power at the time of Jangsu's succession.

In 427, he transfers the Goguryeo capital to from Guknaesong (modern Ji'an on the Sino-Korean border) to …

…P'yonggang (Pyongyang).

Many modern Chinese historians argue that since the early Goguryeo capital had been located in what is now China, the history of that kingdom prior to 427 should be regarded as Chinese history).

There are various reasons for this shift: to prepare for the offensive against Baekje and Silla in the south and to create a greater and more magnificent capital befitting a kingdom that has experienced large-scale expansion.

After moving the capital southward, King Jangsu decides to continue the conquests of his father.

Feng Hong, in order to try to get Liu Song aid, sends a messenger in spring 435 to the Liu Song capital Jiankang to submit as a vassal.

Emperor Wen of Liu Song creates Feng Hong the Prince of Yan, but is unable to provide substantial aid.

Feng Hong now sends his general Tang Zhu to offer tribute to Northern Wei, and claiming illness as the reason that Feng Wangren is not coming.

This reason appears to have been rejected by Northern Wei, and Feng Hong again tries to seek Liu Song aid, but none is forthcoming.

In summer 435, Emperor Taiwu's brother Tuoba Pi, the Prince of Leping again arrives at Helong, and Feng Hong tries to appease him by offering cattle, wine, and armor, but Tuoba Pi's assistant general Qutu Yuan accuses Feng Hong of not sending hostages, and they seize six thousand Northern Yan men and women before withdrawing.

The entire Northern Yan state is by this point not significantly larger than the city of Helong itself, and it is weary of repeated Northern Wei attacks.

Feng Hong's general Yang Min suggests Feng Hong send Feng Wangren as a hostage but Feng Hong refused, instead considering a plan to evacuate his people to his ally Goguryeo.

Yang believes Goguryeo to be undependable but Feng Hong, not to be deterred, sends messengers to Goguryeo seeking aid and an agreement to harbor evacuees.

Feng Hong, emperor of Northern Yan, sends another embassy in 436, offering to send Feng Wangren as a hostage.

Emperor Taiwu, disbelieving Feng Hong's sincerity, refuses, and prepares a final assault.

When he arrives at Helong, however, Feng Hong had already requested assistance from Goguryeo, which sends troops to assist Feng Hong's plans of relocating his people to Goguryeo soil, and because Emperor Taiwu's general Tuxi Bi is drunk, the Northern Wei forces cannot give chase.

In anger, Emperor Taiwu imprisons and then demotes both Tuxi and his deputy, the general E Qing to being common soldiers (although he will subsequently made them generals again).

He now sends messengers to Goguryeo, demanding that Goguryeo turn over Feng Hong.

Goguryeo's King Jangsu refuses, albeit humbly requesting to serve Emperor Taiwu together with Feng Hong.

Emperor Taiwu, at the suggestion of his brother Tuoba Pi, the Prince of Leping, does not immediately launch a campaign against Goguryeo.

(By 438, however, Feng Hong and Goguryeo will have had a falling-out, and King Jangsu will have Feng Hong executed.)

In late 436, the peaceful relations that Northern Wei has had with the Rouran since 431 end or reasons no longer known.

The Rouran continue their harassment of Northern Wei's northern border regions.