Usan-guk, or the State of Usan, occupies Ulleung-do and the adjacent islands during the Korean Three Kingdoms period.

According to the Samguk Sagi, General Kim Isabu of the Silla Dynasty conquers the island nation in 512.

According to Sejong Sillok, Goryeosa, and Mangi Yoram, Usan-guk consisted of Ulleung-do and Usan-do.

Koreans believe Usan-do is Liancourt Rocks (Dokdo in Korea, Takeshima in Japan).

Japanese researchers have claimed the various references to Usan-do refer at different times to Jukdo, its neighboring island Ulleungdo, or a nonexistent island between Ulleungdo and Korea.

The Anastasian Wall is named after the Emperor Anastasius I.

However, there is evidence that the fortification already existed in 469 during the reign of Leo I (r. 457-474) and in 478 in the era of Zeno (r. 476–491), and it was maintained and renewed by Anastasius from 507 to 512.

It stretches from Evcik İskelesi in Çatalca at the Black Sea coast across the Thracian peninsula to …

…the coast of the Sea of Marmara at six kilometers (3.7 miles) west of Silivri (ancient Selymbria).

The wall has a thickness of 3.3 meters (eleven feet) and a height over five meters (16 feet).

It is built complete with towers, gates, forts, ditches and a military way to protect Constantinople from invasions from the west by Huns, Slavs and Bulgars.

A rectangular castrum with dimensions of two hundred and fifty meters (eight hundred and twenty feet) by three hundred meters (nine hundred and eighty feet) exists also in the central section of the wall.

The Anastasian Wall is an almost unknown example of monumental linear fortification dating from antiquity in continental Europe, next only to Hadrian's Wall (CE 122) in England in its complexity.

Anastasius, ending a period of moderate eclectic policy, starts strongly favoring his own monophysitist beliefs.

Areobindus, a general, is living in Constantinople in retirement in 512, when the open advocacy of miaphysite doctrines by Emperor Anastasius has caused great anger among the city's mostly Chalcedonian population.

At one point, according to the chroniclers, the city populace takes up the cry "Areobindus for emperor" and marches to the house of his wife, Anicia Juliana, to proclaim him.

Areobindus however, unwilling to take part in a usurpation, had fled the house and gone into hiding.

Nothing further is known of him, although on account of his age he must have died not long after.

Persian king Kavadh I adopts the doctrine of the Mazdakites in 512 and breaks the influence of the magnates.

The Jewish community revolts at Ctesiphon against Mazdakism and establishes an independent Jewish kingdom; it will last for seven years.

The Ostrogoths conquer the Frankish province of Rouergue in southern Gaul.

The Burgundians become the most prestigious people in Gaul following the death of King Clovis of the Franks in 511.

Gundobad, favored by the court of Constantinople, is awarded the title of magister militum.

King Theodoric grants citizens on Mount Vesuvius exemption from taxes after a severe eruption in southeastern Italy.

The Kingdom of Baekje sends a Confucian scholar to the Yamato court in 513 to assist in the teachings of Confucian thought.

Anastasius has perfected the empire's monetary system, increased its treasury, and proved himself an able administrator of domestic and foreign affairs.

His heretical Monophysite religious policies, however, are the cause of periodic rebellions.

At first professing orthodoxy, Anastasius has gradually adhered more to Monophysite doctrine, which holds that Christ had one, divine nature.

Although this stand has caused great unrest in Constantinople and in the European provinces, it has bought peace with Egypt and Syria.

In Thrace, however, it has inspired rebellion by the military commander Vitalianus.