Sigebert III was a Merovingian king of Austrasia who reigned from 633 until his death in 656. Born around 630 to King Dagobert I, he ascended to the throne as a child. While his political authority was limited by the powerful mayors of the palace, making him one of the dynasty's first ineffective rulers, he was noted for his deep religious devotion. He used his resources to support the church, establishing various religious institutions throughout his kingdom.