[1] It initially included land between the Loire and the Silva Carbonaria, in the north of present-day France, with Paris, Orléans, Tours, Soissons as its main cities.
The same term later referred to a smaller region between the Seine and the Loire rivers known as the regnum Neustriae, a constituent subkingdom of the Carolingian Empire and then West Francia.
[citation needed] In 486 its ruler, Syagrius, lost the Battle of Soissons to the Frankish king Clovis I and the domain was thereafter under the control of the Franks.
With Pope Stephen II's blessing, after 751 the Carolingian Pippin the Short formally deposed the Merovingians and took control of the empire, he and his descendants ruling as kings.
Neustria, along with Aquitaine, formed the major part of Charles West Frankish kingdom carved out of the Empire by the Treaty of Verdun (843).
Charles continued the tradition of appointing an elder son to reign in Neustria with his own court at Le Mans when he made Louis the Stammerer king in 856.
Louis married the daughter of the King of Brittany, Erispoe, and received the regnum from the Breton monarch with the consent of the Frankish magnates.
This unique relationship for Neustria stressed how it had shrunk in size to definitely exclude the Île de France and Paris by this time, as it was distanced from the central authority of Charles the Bald and closer to that of Erispoe.
Louis was the last Frankish monarch to be appointed to Neustria by his father and the practice of creating subkingdoms for sons waned among the later Carolingians.
In 861, the Carolingian king Charles the Bald created the Marches of Neustria that were ruled by officials appointed by the crown, known as wardens, prefects or margraves.