After three months leave in England Gurwood went to Brussels in August 1814 having been appointed ADC to Sir Henry Clinton, who was second in command to the Prince of Orange in the Netherlands. Sir Henry was in Paris when the news broke that Napoleon had escaped from Elba and he was ordered to remove immediately to Tournai. In the hurry and confusion Gurwood offended Clinton and felt obliged to resign as ADC. He rejoined the 10th Hussars to which he had transferred in 1814 and served with them at Waterloo, where his horse was killed under him and he was wounded in the knee.