Gwanggaeto has led several more campaigns against Xianbei as well as against Khitan tribes in Inner Mongolia, which he brings under his control.

In 408, the King sends a peace delegate to Gao Yun, the ruler of Later Yan/Northern Yan, to broker a settlement between the two dynasties, because Gao Yun descends from the Goguryeo royal house as well.

Goguryeo control over the Liaoning region is to remain strong until the Tang Dynasty seizes the area as a part of its war against Goguryeo in the late sixth century.

Murong Chao honors Lady Duan as empress dowager in 408, and creates Lady Huyan empress.

An army dispatched by Honorius lays siege to Constantine in Valentia (modern Valence, France) but soon withdraws.

Arcadius, after a weak thirteen-year reign, dies in his palace on May 1, 408; his seven-year-old son of Arcadius, made coemperor in 402, ascends the throne as Theodosius II, who rules under the domination of his devout Christian sister Pulcheria.

Due to Theodosius' young age, the Praetorian prefect, Anthemius, acts as regent.

Yazdegerd becomes an executor of Arcadius' will and is entrusted with the care of the young Theodosius II until he comes of age.

Relations between Rome and Persia are remarkably good at this time.

Yazdegerd I has relaxed the century-and-a-half-long persecution against Christians, who have been suspected of having been secret allies of the Romans since the time of Shapur II (r. 309-79).

However, because of the attitude of the Persian aristocracy and because of the growing fanaticism of the Christians, Yazdegerd is forced to turn to repression of the nobles.

The Huns under Uldin attack the Eastern Empire in 408, setting fire to various frontier forts and, apparently by treachery, taking control of the Castra Martis, a Roman fortress (castra) in the Roman province of Dacia ripensis on the modern site of Kula, in Vidin Province in Bulgaria.

The Romans try to negotiate, but Uldin demands an exorbitant gold tribute in return for his withdrawal.

This demand is rejected and the Romans begin to push the Huns back across the Danube.

Constantine, joined by Roman legions from Spain, has by May 408 made Arles his capital, where he appoints Apollinaris, the grandfather of Sidonius Apollinaris, as prefect.

In the summer of 408, as the Roman forces in Italy assemble to counterattack, Constantine has other plans.

Hispania is a stronghold of the House of Theodosius and loyal to the ineffectual emperor.

Fearful that several cousins of the emperor Honorius will organize an attack from that direction while troops under Sarus and Stilicho attack him from Italy in a pincer maneuver, Constantine strikes first at Hispania.

He summons his eldest son Constans from the monastery where he is dwelling, elevates him to caesar, or junior emperor, and sends him with the general Gerontius towards Hispania.

Alaric now marches to the province of Noricum (roughly central Austria), assumes control of the defeated Ostrogoths' base, and demands compensation for the trouble he has been put to.

His price is high—four thousand pounds of gold—but despite considerable opposition, Stilicho persuades the Roman Senate to pay it in exchange for proffered Gothic service.

The cousins of Honorius are defeated without much difficulty and two—Didymus and Theodosiolus—are captured, while two others—Lagodius and Verianus—manage to escape to safety in Constantinople.

Constans executes the two captives and leaves his wife and household at Saragossa under the care of Gerontius to return to report to Arles.

Stilicho's influence has declined.

It is rumored that he wishes to have his son Eucherius elevated to the throne.

Reports reach him early in 408 that his army is disaffected.

Now comes news of the premature death, on May 1, of the Eastern emperor, Arcadius, and Stilicho proposes to go to Constantinople.

He may also have intended to give Alaric a senior official position and send him against the rebels in Gaul.

Before he can do so, while he is away at Ticinum at the head of a small detachment, a bloody coup against his supporters takes place at Honorius's court.

It is led by Stilicho's own creature, one Olympius, who had spread the rumor that Stilicho is preparing to put his own son on the Eastern throne; the troops kill nearly all of the officials present on August 13.