SOURCES:
Thierri=Theuderic III, King de Neustrie (Rosamond, Frankish kingdom
under Carolingians.)
(Paul, Nouveau Larousse Universel.) (Stuart, Royalty
for Commoners, Page 90, Line 123-46.) (Andre Castelot, Histoire de La France, Tome 1, Pages 250 - 259, 256).
Born: in 651 in Neustrie, son of Clovis II, King de Bourgogne and Sainte Bathilde. Some sources assert that Thierry III was born in 651 while others claim it was circa 654. Note - between 673 and 690: Thierri III became King of Neustrie upon the death of Clotaire III between 10 March and 15 May 673. The Crown was given him by Ebroin, Major Domo. It is Ebroin's excesses which caused the Greats [Optimates] to rebel in 674 and to call upon Childeric II, King of Austrasia for help. Thierri III was de-throned in 674 by Childeric II who died in 675 allowing Thierri III to re-claim the throne. In 674, he was shaven and relegated to Saint-Denis. Ebroin was exiled to the Monastery of Luxeuil [Haute-Saone]. In 676, Thierry III left Saint-Denis to become King of Neustria and of Burgundy with the help of Major Domo Leger. Ebroin, however, first supports Clotaire III, a son of Clovis III, and then he swings to Thierry III.
Thierry III for his part is first and foremost King of Neustria and of Burgundy and the Greats [Optimates] of Austrasia want a King of their own. Thus, they find Dagobert II, son of Sigebert III, who had been exiled in Ireland. For all practical purposes, Dagobert II is King of Austrasia, whereas Ebroin rules Neustria and Burgundy in the name of Thierry III. By 680, through the death in 679 of Dagobert II, Thierry III is sole King of Gaule. But in reality the antagonism between the Neustrians and the Austrasians was quite aggravated. Austrasia is at that time governed by the grandson of Pepin de Landen, Pepin II, who makes himself Duke of Austrasia, supported by his brother Martin. In the Summer of 680, the two armies join in battle at Leucofao [known today as Bois-du-Fay] in the Ardennes. The Austrasians are defeated and Pepin escapes. Martin is taken prisoner in Laon, where he had sought refuge. Ebroin had promised to let him live, and of course, he rushed to have him executed. Within 3 years Ebroin is himself assassinated by one Ermenfroy who takes refuge in Austrasia. In 687, Pepin II with the help of the Greats [Optimates] of Neustria, invades Neustria from the North-East. Though Thierry III was vanquished at the Battle of Tertry [three leagues from Saint-Quentin] by Pepin II, the latter still recognized Thierry III as King of Neustrie. Married before 674: Amalberge, daughter of Wandregisis and Farahild. Died: between March 691 and April 691.
Thierry III died in March or April, and his son Clovis IV succeeds him, though he is barely 9 years of age. Thus, Pepin II [Pepin of Herstal] remains the true ruler.