By the time of Sigibert the Merovingian dynasty was almost powerless, real power having shifted to the hereditary mayors of the palace. When Sigibert died in 657, Grimoald had the rightful heir, Dagobert, sent to Ireland "on pilgrimage," while he installed the boy Childebert as his puppet on the throne. This caused opposition among the nobles, however, which resulted in 662 in Grimoald's murder and Childebert's overthrow and probably his death as well.