In 1848 he entered the Royal Military Academy at Woolwich, where he remained till 1852, when, at the age of nineteen, he received his commission in the Royal Engineers. Although he was an adept at surveying and at fortification, two branches of military knowledge which served him well in after years, he was deficient in mathematics, and consequently did not make much progress. An event which took place here might have had very serious consequences, and shows that even then he had the daring nature which afterwards characterised him. For some reason it became necessary to restrain the cadets when leaving the dining-hall, the approach to which was by a narrow staircase. At the top of this staircase stood the senior corporal, with outstretched arms, facing the cadets. This was too much for one so full of fun and energy and so reckless of consequences as Gordon; so, putting down his head, he charged, and butting the corporal in the pit of the stomach, sent him flying down the staircase and through a window beyond. Fortunately the corporal was unhurt, but Gordon was perilously near dismissal, and having his military career cut short. The act of insubordination was, however, overlooked by the authorities, but that it did not subdue his spirit is evident from the fact that on another occasion, when told by Captain Eardley Wilmot that he would never make an officer, he tore the epaulets from his shoulders and threw them at the feet of his superior. This officer, afterwards General Eardley Wilmot, became one of his greatest friends. Later on, for another offence, in which many were concerned, and of which it is doubtful if Gordon really was guilty, he was deprived of half a year's seniority in the army. This punishment really did him a good turn, for it enabled him to secure a commission in the Royal Engineers instead of the Royal Artillery, to which he would otherwise have been posted. On the 23rd June 1852 Gordon was gazetted to the Engineers, and on the 29th November 1854 he was ordered to Corfu. As the Crimean War was going on he was much disappointed at this order, and at first attributed it to his mother's influence, who, he thought, wanted him to be sent to a safe place. Through the influence of Sir John Burgoyne, an old family friend, his destination was changed, and on the 4th of December, during that bitterly cold winter, he writes, "I received my orders for the Crimea, and was off the same day." This was not the only time that he exhibited such promptitude in leaving his native land at the call of his country. Thirty years afterwards he left England for the Soudan the very day he received his orders.