Berthar was the mayor of the palace

Mayor of the Palace

Mayor of the Palace was an early medieval title and office, also called majordomo, from the Latin title maior domus , used most notably in the Frankish kingdoms in the 7th and 8th centuries....

 of Neustria

Neustria

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...

 and Burgundy

Kingdom of Burgundy

Burgundy is a historic region in Western Europe that has existed as a political entity in a number of forms with very different boundaries. Two of these entities - the first around the 6th century, the second around the 11th century - have been called the Kingdom of Burgundy; a third was very...

 from 686 to 687. He was the successor of Waratton

Waratton

Waratton, Waratto, or Warato was the mayor of the palace of Neustria and Burgundy on two occasions, owing to the deposition he experienced at the hands of his own faithless son. His first term lasted from 680 or 681 to 682, when his son Gistemar deposed him and took over the office...

, whose daughter Anstrude he had married.

Unlike Waratton, however, Berthar did not have peace with Pepin of Heristal. In 687, Pepin defeated him and Theuderic III

Theuderic III

Theuderic III was the king of Neustria on two occasions and king of Austrasia from 679 to his death in 691. Thus, he was the king of all the Franks from 679...

 at Tertry

Tertry

Tertry may refer to*The Battle of Tertry or*Tertry, Somme, a commune in the Somme département in the Picardie region of France....

 in the Vermandois

Vermandois

Vermandois was a French county, that appears in the Merovingian period. In the tenth century, it was organised around two castellan domains: St Quentin and Péronne . Pepin I of Vermandois, the earliest of its hereditary counts, was descended in direct male line from the emperor Charlemagne...

. Many fled to the nearby abbeys of Péronne

Péronne, Somme

Péronne is a commune of the Somme department in Picardie in northern France.It is close to where the Battles of the Somme took place during World War I...

 and Saint-Quentin

Saint-Quentin, Aisne

Saint-Quentin is a commune in the Aisne department in Picardy in northern France. It has been identified as the Augusta Veromanduorum of antiquity. It is named after Saint Quentin, who is said to have been martyred here in the 3rd century....

. Berthar and Theuderic III withdrew themselves to Paris

Paris

Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...

. Pepin followed them and eventually forced a peace treaty with the condition that Berthar leave his office. In the ensuing quarrels, Berthar killed his mother-in-law Ansfled. Berthar fled. His wife married Pepin's eldest son Drogo

Drogo of Champagne

Drogo , son of Pepin the Middle and Plectrude, was the duke of Champagne by appointment of his father in 690 and duke of Burgundy from the death of Nordebert in 697...

, duke of Champagne

Champagne (province)

The Champagne wine region is a historic province within the Champagne administrative province in the northeast of France. The area is best known for the production of the sparkling white wine that bears the region's name...

, and Pepin became the mayor of the palace of Neustria and Burgundy without opposition.

Berthar died in either the Autumn of 688 or early 689.