Erchinoald (also Erkinoald and, in French, Erchenout) succeedsAega as the mayor of the palace of Neustria in 641 and succeeds Flaochad in Burgundy in 642 and remains such until his death in 658.

According to Fredegar, he was a relative (consanguineus) of Dagobert I's mother.

Chaume cites the Notitia de Fundatione Monasterii Glanderiensis to suggest that Erchinoald was descended from the Gallo Roman senator Ansbertus through a son of that senator also named Erchinoald and that Erchinoald's son Leudesius, and was therefor a descendant of the gallo-roman families of the Syagrii and Ferrèoli.

Erchinoald's relationship with Merovingian King Dagobert has been proposed to have been through his mother Gerberga, daughter of Burgundian dux Ricomeres (fl.

575) and Bertrude, her putative sister and mother of King Dagobert.

Herchenfrida (Erchinfreda), mother of St Desiderius of Cahors will have also been of this family as is further evidenced inter alia by that Gallo Roman saint's close ties to King Dagobert, and a brother named "Syagrius".