[4] The dispute ended abruptly when in December 1330 the documents used by Robert of Artois to support his claim were found to be forged on his instructions.

In 1340, Odo first fought in Hainaut,[6] helped capture the town of Antoing and later defended Saint-Omer in the battle there against Robert III of Artois.

[7] During the summer the French government became aware of plans for an Anglo-Flemish army under Robert of Artois to attack on Saint-Omer.

[7] The slow progress of the English army also allowed further reinforcements led by John I, Count of Armagnac to arrive.

[7] Contrary to orders some hotheads charged out, their attack was beaten off, but their flight caused the Flemings to abandon their defensive works in pursuit.

[7] During the battle the Duke got into a fierce fight with the English and Brugeois contingents and barely escaped back behind the walls.

[8] He took part in the War of the Breton Succession as a partisan of Charles of Blois serving as advisor to his nephew John, Duke of Normandy, during the latter’s campaign in Brittany autumn 1341.

He served together with the Duke of Normandy and the Chancellor of France, Guillaume Flote, as French ambassadors to a peace conference at Avignon in the summer 1344.

The Duke of Burgundy followed John of Normandy south together with a substantial number of northern nobles and such dignitaries as Raoul II of Brienne, Count of Eu, the Constable of France, both Marshals and the Master of Crossbowmen.