He fought at the Battle of Poitiers in 1356 and in 1360 after the Treaty of Brétigny, and without employ, in 1361 he led a band of brigands, with Bertucat d'Albret into Languedoc, Roussillon, Toulouse and Rouergue districts.
In 1362, with Bertucat he took Montbrun, plundered Saint-Flour then participated with Petit Meschin at the Battle of Brignais against Jacques de Bourbon Count of La Marche.
In 1363, refusing to go to Italy with most of the other routiers, he returned to plunder Languedoc area with Meschin, Louis Rabaud, Arnaud du Solis and Espiote, taking Brioude on 13 September.
The troops of Seguin Badefol also made raids in Puy, Chaise-Dieu in Clermont, Montferrand, Chilhac, Riom, Nonnette, Issoire, Saint-Bonnet Arsis and ravaged Auvergne.
Here Charles II of Navarre employed him, but while in his service he was poisoned – either with figs at Pamplona in December 1365, or according to historian Germain Butaud, at Falces in February 1366 after eating quince and pears.