Wood served as a midshipman in the Crimean War during the siege of Sebastopol. Seriously wounded in an attack on the Redan, Wood was mentioned in dispatches. He then left the Royal Navy to join the British Army, becoming a cornet in the 13th Light Dragoons and then a lieutenant in the 17th Lancers. In India, he saw action at Rajghur, Sindwaho, Kharee, and Barode during the Indian Mutiny.
On 19 October 1858 during an action at Sinwaho, twenty-year-old Lieutenant Wood of the 17h Lancers was in command of a troop of light cavalry, and attacked almost single-handed a body of rebels, whom he routed. At Sindhora, with the help of a daffadar and a sowar, he rescued a local merchant from a band of robbers who had taken their captive into the jungle, where they intended to hang him. For this, Wood was awarded the Victoria Cross.
In 1861, Wood was promoted to captain and in 1862, he became a brevet major in the 73rd (Perthshire) Regiment of Foot. In 1865, he left the infantry for the cavalry again. After a stint as an aide-de-camp in Dublin, Wood was given a staff position until 1871, when he became a full major in the 90th Foot. In 1867, he married Mary Pauline Southwell, the sister of the 4th Viscount Southwell.
In 1873, Wood was promoted brevet lieutenant-colonel and in 1874, he served in the Ashanti War. Until 1878, Wood was a member of the staff at Aldershot.