It included the original Frankish-ruled territories within what had been the northernmost part of Roman Gaul, and cities such as Cologne, Trier and Metz.

At the same time, the initial powerbase of Clovis himself was the more Romanized part of northern Gaul, lying southwest of Austrasia, which came to be known as Neustria.

In 880, the Treaty of Ribemont was the last such major agreement, which established formal boundaries eastern, central, and western sub-kingdoms that remained important throughout the Middle Ages.

The term designated the original territory of the Franks in contrast to Neustria, which apparently meant the "(new) western land".

It bordered on Frisia and Saxony to the north, Thuringia to the east, Swabia and Burgundy to the south and to Neustria to the southwest.

In the High Middle Ages, its territory became divided among the duchies of Lotharingia and Franconia in Germany, with some western portions including Reims and Rethel passing to France.

Its exact boundaries were somewhat fluid over the history of the Frankish sub-kingdoms, but Austrasia can be taken to correspond roughly to the territory of present-day Luxembourg, parts of eastern Belgium, north-eastern France (Lorraine and Champagne-Ardenne), west-central Germany (the Rhineland, Hesse and Franconia) and the southern Netherlands (Limburg, North Brabant, with a salient north of the Rhine including Utrecht and parts of Gelderland).

After the death of the Frankish king Clovis I in 511, his four sons partitioned his kingdom amongst themselves, with Theuderic I receiving the lands that were to become Austrasia.

The first Austrasian mayors came from the Pippinid family, which experienced a slow but steady ascent until it eventually displaced the Merovingians on the throne.

In 623, the Austrasians asked Chlothar II for a king of their own and he appointed his son Dagobert I to rule over them with Pepin of Landen as regent.

With the Battle of Tertry in 687, Pepin of Heristal defeated the Neustrian king Theuderic III and established his mayoralty over all the Frankish kingdoms.