The territory of Neustria originated in A.D. 511, made up of the regions from Aquitaine to the northern seacoast approximating most of the north of present-day France. The two main cities were Paris and Soissons. Previously, Neustria was the western part of the kingdom of the Franks during the sixth to eighth centuries under the rule of the Merovingians. The distinct area originated at the time of the death of Clovis I (reigned 482-511) when his lands were divided between his sons.
The constant re-divisions by his offspring resulted in many rivalries that, for more than two hundred years, kept Neustria in almost constant warfare with Austrasia, the eastern portion of the Frankish kingdom.
Despite the wars, Neustria and Austrasia were only reunited briefly on a few occasions, the first time by Clotaire I during his reign from 558 to 562. The struggle for power continued with the widow of King Chilperic I (reigned 566-584) when a bitter war was led by Queen Fredegund of Neustria, mother of the new king Clotaire II (reigned 584-628).
After his mother's passing and burial in Saint Denis Basilica in Paris (597), Clotaire II continued the struggle against Queen Brunhild of Austrasia (d. 613) and was victorious, but only for a short time. Finally under Dagobert I (reigned 628-637) the ongoing generational war resulted in another temporary unification but by then the authority of the warring kings began to decline as the mayors of the palace rose to prominence.
Pippin's descendants, the Carolingians, continued to rule the two realms as mayors. With the Pope's blessing, after 751 the Carolingian Mayor of the Palace, Pippin the Short, formally deposed the Merovingians and took control of the empire, he and his descendants ruling as kings.
Neustria, Austrasia, and Burgundy were then united under one authority and the names Neustria and Austrasia gradually disappeared.
For a list of rulers of Neustria, see the list of Frankish Kings.