Battle of Tertry

The Battle of Tertry was an important engagement in Merovingian Gaul between the forces of Austrasia on one side and those of Neustria and Burgundy on the other. It took place in 687 at Tertry, Somme.

The powerful Austrasian mayor of the palace, Pepin of Herstal, had concluded peace with his Neustrian counterpart, Waratton, in 681. However, Waratton's successors had renewed the conflict between Austrasia and Neustria which was common in times of disunion: though the Frankish realm was then united under Theuderic III, who inherited Austrasia in 679. The king, born and raised in Neustria and a Neustrian at heart, and the nobles of Neustria and Burgundy, under their mayor, Berthar, invaded Austrasia territory. Berthar and Theuderic were routed at Tertry and the Austrasians had the field. Their supremacy vindicated on a battlefield, the victors forced Berthar out of office and Pepin appointed Nordebert to act on his behalf in Neustria and Burgundy. The king was forced to recognise Pepin's mayorship over the entire realm in exchange for remaining sole king.

The legacy of the battle was the further diminution of royal authority, for once again a Merovingian had been definitively defeated in battle; the supremacy of Austrasia over the rest of the realm, characterised by later conquests to the east and the Aachen-centred Carolingian Empire; the undisputed right to rule of the Arnulfing clan, Pepin even taking the title of dux et princeps Francorum; and, finally, the personal gains to Pepin, who "reigned," as one chronicle put it, thereafter over all the Franks for 27 more years.