Pepin II of Heristal (635–714) of the rich and powerful Pippinid family, was appointed ‘Mayor of the Palace’ in 680, and at once found himself in conflict Martin of Laon and Ebroin of Neustria. In 687, at Tertry on the River Somme, the Austrasian army under Pepin overwhelmingly defeated the Neustrians. He conquered the Burgundians in 711 and thus became mayor of all three kingdoms and at once designated himself ‘Duke and Prince of all the Franks’. Over the ensuing years Pepin also subjugated the Alamani, the Frisians and the Franconians; in 692 he captured Utrecht and secured control of the vital trade route via the Rhine to the North Sea; and he started spreading Catholicism throughout Germany. Childebert III succeeded his father as the head of three Frankish kingdoms, Neustria, Austrasia and Burgundy, in 711. However, he was a puppet ruler; real power still remained with the Mayor of the Palace, Pippin of Heristal. When Childebert III died in 714, he was succeeded by Dagobert III. During Pepin’s rule there was a further diminution of royal authority and its ‘divine right’, enabling him to name as his heir his grandson Theudoald, a decision later hotly contested by his son Charles Martel.