Childebert III the Adopted (Childebertus Adoptivus) was a Frankish

Franks

The Franks were a confederation of Germanic tribes first attested in the third century AD as living north and east of the Lower Rhine River. From the third to fifth centuries some Franks raided Roman territory while other Franks joined the Roman troops in Gaul. Only the Salian Franks formed a...

 King. When King Sigebert III

Sigebert III

Sigebert III was the king of Austrasia from 634 to his death; probably on 1 February 656, or maybe as late as 660. He was the eldest son of Dagobert I....

 died in 656, Grimoald the Elder

Grimoald the Elder

Grimoald I , called the Elder , was the Mayor of the Palace of Austrasia from 643 to 656. He was the son of Pepin of Landen and Itta....

 had Sigebert's son Dagobert II

Dagobert II

Dagobert II was the king of Austrasia , the son of Sigebert III and Chimnechild of Burgundy. The Feast Date of St Dagobert II is 23 December -Biography:...

 shorn of hair and sent to an Irish

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

 monastery

Monastery

Monastery denotes the building, or complex of buildings, that houses a room reserved for prayer as well as the domestic quarters and workplace of monastics, whether monks or nuns, and whether living in community or alone .Monasteries may vary greatly in size – a small dwelling accommodating only...

 and then proclaimed his own son king of Austrasia.

Grimoald, his son, and perhaps his brother-in-law Ansegisel

Ansegisel

Ansegisel was the son of Saint Arnulf, bishop of Metz and his wife Saint Doda. He served King Sigbert III of Austrasia as a duke and domesticus...

 (who had married the daughter of Pepin of Landen), were finally seized and turned over to the 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...

, Clovis II

Clovis II

Clovis II succeeded his father Dagobert I in 639 as King of Neustria and Burgundy. His brother Sigebert III had been King of Austrasia since 634. He was initially under the regency of his mother Nanthild until her death in her early thirties in 642...

, who had them killed. There are two differing accounts of his death, however. Either Clovis and his mayor of the palace, Erchinoald

Erchinoald

Erchinoald succeeded Aega as the mayor of the palace of Neustria in 641 and succeeded Flaochad in Burgundy in 642 and remained such until his death in 658. According to Fredegar, he was a relative of Dagobert I's mother...

, captured and executed him in 657 or Clotaire III

Clotaire III

Chlothar III was the eldest son of Clovis II, king of Neustria and Burgundy, and his queen Balthild...

 of Neustria annexed Austrasia in 661, deposing the young usurper and executing them both the next year.

The family reappeared in politics with the rise of Ansegisel's son, Pepin II of Herstal

Herstal

Herstal, formerly known as Heristal, or Héristal, is a municipality of Belgium. It lies in the country's Walloon Region and Province of Liege along the Meuse river. Herstal is included in the "Greater Liège" agglomeration, which counts about 600,000 inhabitants...

.