The territory of Neustria or Neustrasia, meaning "new [western] land", originated in 511, made up of the regions from Aquitaine to the English Channel, approximating most of the north of present-day France, with Paris and Soissons as its main cities. Thus Neustria formed the western part of the kingdom of the Franks under the rule of the Merovingian dynasty during the sixth to eighth centuries. The distinct area originated at the time of the death of Clovis I (reigned 482–511), when his sons divided his lands between them. It later became a term for the region between the Seine and the Loire rivers known as the regnum Neustriae, a constituent subkingdom of the Carolingian Empire and then West Francia. The Carolingian kings also created a March of Neustria which was a frontier duchy against the Bretons and Vikings that lasted until the Capetian monarchy in the late tenth century.
Neustria was also employed as a term for northwestern Italy during the period of Lombard domination. It was contrasted with the northeast, which was likewise called Austrasia, the same term as given to eastern Francia.

Merovingian kingdom
In 748, the brothers Pepin the Short and Carloman gave their younger brother Grifo twelve counties in Neustria centred on that of Le Mans. This polity was termed the ducatus Cenomannicus, or Duchy of Maine, and this was an alternative name for the regnum of Neustria well into the ninth century.
The term "Neustria" took on the meaning of "land between the Seine and Loire" when it was given as a regnum (kingdom) by Charlemagne to his eldest son, Charles the Younger, in 790. At this time, the chief city of the kingdom appears to be Le Mans and it was there that the royal court of Charles was established. Under the Carolingians, the chief duty of the Neustrian king was to defend the sovereignty of the Franks over the Bretons.
In 817, Louis the Pious granted Neustria to his eldest son Lothair, but following his rebellion in 831, he gave it to Pepin, and following the latter's death in 838, to Charles the Bald. 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 Carolings.

Carolingian subkingdom

Main article: March of Neustria Carolingian march

Rulers
The precise division of Francia into a Neustrian, Austrasian, and Burgundian kingdom dates only from the late sixth century, so earlier kings who ruled from Soissons or Paris are here excluded.

Chlothar II, 584–629
Dagobert I, 629–639
Clovis II, 639–657
Chlothar III, 657–673
Theuderic III, 673
Childeric II, 673–675
Theuderic III, 675–691
Clovis IV, 691–695
Childebert III, 695–711
Dagobert III, 711–715
Chilperic II, 715–721
Theuderic IV, 721–737
Childeric III, 743–751 Merovingian kings
These were the chief officers of the kings and gradually became the de facto rulers in the name of the kings.

Landric, until 613
Gundoland, 613–639
Aega, 639–641
Erchinoald, 641–658
Ebroin, 658–673
Wulfoald, 673–675
Leudesius, 675
Ebroin, 675–680 (again)
Waratton, 680–682
Gistemar, 682
Waratton, 682–686 (again)
Berthar, 686–688
Pepin of Heristal, 688–695
Grimoald II, 695–714
Theudoald, 714–715
Ragenfrid, 715–718
Charles Martel, 718–741
Pepin the Short, 741–751 Mayors of the palace
Louis was chased from Le Mans in 858 following the assassination of Erispoe in November 857.

Charles the Younger, 790–811
Lothair I, 817–831
Pepin, 831–838
Charles the Bald, 838–856
Louis the Stammerer, 856–879 Historiography