Adalgisel or Adalgis 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...

 duke

Dux

Dux is Latin for leader and later for Duke and its variant forms ....

 and 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 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...

. He assumed that office in December 633

633

Year 633 was a common year starting on Friday of the Julian calendar. The denomination 633 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.- Europe :* Oswald of Bernicia becomes Bretwalda.* Osric...

 or January 634

634

Year 634 was a common year starting on Saturday of the Julian calendar. The denomination 634 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.- British Isles :* Oswald of Northumbria defeats...

 at the same time that 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....

 assumed the kingship. Along with Cunibert, Bishop of Cologne

Cunibert, Bishop of Cologne

Saint Cunibert, Cunipert, or Kunibert was the ninth Bishop of Cologne from 627 to his death. Contemporary sources only mention him between 627 and 643....

, he acted as regent

Regent

A regent, from the Latin regens "one who reigns", is a person selected to act as head of state because the ruler is a minor, not present, or debilitated. Currently there are only two ruling Regencies in the world, sovereign Liechtenstein and the Malaysian constitutive state of Terengganu...

 for the young king. Adalgisel, Cunibert, and Sigebert were all appointed by Dagobert I

Dagobert I

Dagobert I was the king of Austrasia , king of all the Franks , and king of Neustria and Burgundy . He was the last Merovingian dynast to wield any real royal power...

.

Adalgisel and Grimoald led the Austrasian army against the Thuringii

Thuringii

The Thuringii or Toringi were a Germanic tribe which appeared late during the Völkerwanderung in the Harz Mountains of central Germania around 280, in a region which still bears their name to this day — Thuringia. They evidently filled a void left when the previous inhabitants — the...

 sometime around 639

639

Year 639 was a common year starting on Friday of the Julian calendar. The denomination 639 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.- Europe :* Clovis II succeeds Dagobert I as king of the...

, but their magnates defected and they were forced to concentrate on protecting the young king's life. His forces were subsequently defeated by Duke Radulf. Not long after, he ceased to be duke and was replaced by Pepin of Landen, probably following the nearly concurrent death of Dagobert. Though he lost his office, there is no evidence that he died at that time and some charters referring to a person of the same name may refer to him, thus indicating his survival long after the fact.

He left a son Bobo, who had accompanied him into battle against the Thuringii, and was later Duke of Auvergne.

Sources

• Foundation for Medieval Genealogy. Merovingian Nobility.
• Wallace-Hadrill, J. M.
  John Michael Wallace-Hadrill
  John Michael Wallace-Hadrill CBE was Professor of Mediaeval History at the University of Manchester , a Senior Research Fellow of Merton College in the University of Oxford , Chichele Professor of Modern History, University of Oxford and a Fellow, All Souls College, Oxford...
  
  , translator. The Fourth Book of the Chronicle of Fredegar with its Continuations. Greenwood Press: Connecticut, 1960.
• Bachrach, Bernard S.
  Bernard Bachrach
  Bernard S. Bachrach is an American historian and a professor of history at the University of Minnesota. He specialises in the Early Middle Ages, mainly on the topics of Medieval warfare, Medieval Jewry, and early Angevin history...
  
  Merovingian Military Organization, 481–751. Minneapolis: University of Minnesota Press, 1971.