[2] He passed the Military Instruction Class at Eastney in 1885 with honours and special mention in topography.

[16][17] In 1901–1902 he commanded an expedition to the Sudd to remove vegetable obstructions to navigation on the Upper White Nile.

Of his time in the Sudan, M. W. Daly described Matthews as "one of the most indefatigable and conscientious military administrators the government had."

On the outbreak of the First World War, Matthews was given command of the Plymouth Battalion of the Royal Naval Division.

On 18 December 1915, Matthews was appointed a Companion of the Order of St Michael and St George "in recognition of his services in command of the Plymouth Battalion, Royal Marine Brigade, Royal Naval Division, at the Dardanelles.

In 1916, he was seconded for service with the British Army[23] and was given command of the 198th (East Lancashire) Brigade.