Bertrada also called Berthe or Bertree, and perhaps a Merovingian princess, is known to be the mother of Caribert of Laon

Caribert of Laon

Caribert , Count of Laon, was the maternal grandfather of Charlemagne. He was the father of Charles's mother, Bertrada of Laon. Only his mother is known from contemporary records. In 721, Caribert signed, with his mother Bertrada of Prüm , the foundation act of the Abbey of Prüm...

, with whom she is co-founder and benefactor of the Prüm Abbey

Prüm Abbey

Prüm Abbey is a former Benedictine abbey in Prüm/Lorraine, now in the diocese of Trier , founded by a Frankish widow Bertrada, and her son Charibert, count of Laon, on 23 June 720. The first abbot was Angloardus....

. They founded the abbey in 721.

Through Charibert's daughter Bertrada of Laon

Bertrada of Laon

Bertrada of Laon, also called Bertha Broadfoot , was a Frankish queen.- Biography :...

, wife of Pippin the Younger

Pippin the Younger

Pepin , called the Short or the Younger , rarely the Great , was the first King of the Franks of the Carolingian dynasty...

, Bertrada is the great-grandmother of Charlemagne

Charlemagne

Charlemagne was King of the Franks from 768 and Emperor of the Romans from 800 to his death in 814. He expanded the Frankish kingdom into an empire that incorporated much of Western and Central Europe. During his reign, he conquered Italy and was crowned by Pope Leo III on 25 December 800...

. Her husband is unknown for certain.

Two alternative solutions to the question of her parentage have been suggested:

• She was daughter of the seneschal
  Seneschal
  A seneschal was an officer in the houses of important nobles in the Middle Ages. In the French administrative system of the Middle Ages, the sénéchal was also a royal officer in charge of justice and control of the administration in southern provinces, equivalent to the northern French bailli...
  
   and Pfalzgraf Hugobert
  Hugobert
  Hugobert was a seneschal and a count of the palace at the Merovingian court during the reigns of Theuderic III and Childebert III. He was a grandson of the dux Theotar, and it is assumed, but not proven, that his father was a certain Chugus, who in 617 became mayor of the palace of Austrasia...
  
   and Irmina of Oeren.
• She was daughter of 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...
  
  , king 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 Austrasia
  Austrasia
  Austrasia formed the northeastern portion of the Kingdom of the Merovingian Franks, comprising parts of the territory of present-day eastern France, western Germany, Belgium, Luxembourg and the Netherlands. Metz served as its capital, although some Austrasian kings ruled from Rheims, Trier, and...
  
  , and Clotilda of Heristal.