When Condé joined the party of the Fronde Bussy joined him, but a fancied slight on the part of the prince finally decided him for the royal side. He fought with some distinction both in the civil war and on foreign service and, buying the commission of "mestre de camp" in 1655, he went on to serve under Turenne in Flanders. He served there in several campaigns and distinguished himself at the Battle of the Dunes (1658) and elsewhere; but he did not get on well with his general, and his quarrelsome disposition, his overweening vanity and his habit of composing libellous "chansons" made him eventually the enemy of most persons of position both in the army and at court.