 This could not have been done if Grimoald had not secured Sigibert III's support.The Pippinids already gained royal patronage from Pippin I's support, but this was further bolstered by Grimoald's role in Duke Radulf of Thuringia's rebellion.Just prior to Otto's assassination, in c. 640 Radulf revolted against the Merovingians and made himself King of Thuringia.