George was keen to participate in the war against France in Flanders, but his father refused to let him join the army in an active role until he had a son and heir. In early 1707 George's hopes were fulfilled when Caroline gave birth to a son, Frederick. In July Caroline fell seriously ill with smallpox, and George caught the infection after staying by her side devotedly during her illness. They both recovered. In 1708 George participated in the Battle of Oudenarde in the vanguard of the Hanoverian cavalry; his horse and a colonel immediately beside him were killed, but George survived unharmed. The British commander, Marlborough, wrote that George "distinguished himself extremely, charging at the head of and animating by his example [the Hanoverian] troops, who played a good part in this happy victory". Between 1709 and 1713 George and Caroline had three more children, all girls: Anne, Amelia, and Caroline.