King of the Franks (721-737).
Although Theodoric, Dagobert III's son, succeeded Chilperic II in 721 A.D, he reigned under the total control of Charles Martel, Mayor of the Palace. The latter launched countless campaigns against the Friesians and Saxons, forced Thuringia and Bavaria to surrender and halted the Saracen advance in Poitiers (732 A.D). When Theodoric IV died, Charles Martel left the Merovingian throne vacant. He himself died in 741 A.D.