Riddell was commissioned into the British Army as a
second lieutenant into the 5th Regiment of Foot (which later became the Northumberland Fusiliers and, later still, the
Royal Northumberland Fusiliers) on 11 August 1880, and was promoted to
lieutenant on 1 July 1881. He served in the
Hazara Expedition of 1888, where he was
mentioned in despatches, and the following year was promoted to
captain on 27 January 1890, although this was later antedated to 18 November 1889. In October 1899 the
Second Boer War broke out between the United Kingdom and the
Boer Republics in what is now
South Africa. Riddell served with the 2nd Battalion of his regiment, now the Northumberland Fusiliers, which embarked for South Africa in November 1899 and was placed in a brigade under General
Sir William Gatacre. Riddell took part in operations in
Cape Colony, south of
Orange River, from 1899 to 1900, during which he was promoted to
major on 10 January 1900. He was appointed
second-in-command of his battalion on 23 November 1901. He was made a lieutenant colonel on 15 August 1904 and took command of a battalion of his regiment. He served as his battalion's
commanding officer for four years, during which time he was promoted to brevet colonel on 15 August 1907. He relinquished command in August 1908 and then went on
half-pay. He was advanced in rank to colonel on 10 February 1909. In July 1911, after almost three years on half-pay, he reverted to normal pay and assumed command of the Northumberland Brigade, part of the Northumbrian Division, a
Territorial Force formation, which was to be his final command. He was promoted to the temporary rank of brigadier general on 5 August 1914, the day after the
British entry into World War I. He led his brigade to the
Western Front in April 1915, where he was killed. == References ==