Disappointed in his ambitions, Lambert II broke with Charles the Bald and turned to Nominoe, Duke of Brittany, who was then in almost open revolt against the Franks.
At the junction of the diocese of Alet and county of Nantes, on the Roman road of Angers Carhaix he surprised the Breton army led by Nominoe's son Prince Erispoe.
[2] Shortly afterwards, however, the timely arrival of Lambert's troops allowed Erispoe to counter-attack in force, defeating Renaud.
[1] However, other sources assert that Lambert killed Renaud and that the Viking force arrived shortly afterwards, looking for plunder.
Recent studies suggest that another of Renaud's sons Ragenold became Count of Herbauges, then Maine and Marquis of Neustria.