On the morning of 15 June, as the French Army of the North advanced into Belgium, the 14th Division led the IV Corps column of march. Near Florennes, Bourmont halted his division. On the pretence of scouting ahead, he and his staff, rode ahead with a squadron of lancers. After gaining a suitable distance from French lines, he sent the lancers back with a letter for Gérard. In the missive, he explained that he was deserting but promised, "They will not get any information from me which will injure the French army, composed of men I love." He and his staff put the white Bourbon cockade on their hats and galloped for the nearest Prussian position. He immediately handed over Napoleon's operational plans to the Prussians. Gebhard von Blucher's chief of staff August von Gneisenau was pleased to receive this windfall. However, Blucher had no use for turncoats and called Bourmont a traitor to his face. When Gneisenau noted that Bourmont was wearing the white cockade, making them allies, Blucher screamed, "Cockade be damned! A dirty dog is always a dirty dog!"