Queen's South Africa Medal 1899-1902, with five clasps: 'Tugela Heights', 'Orange Free State', 'Relief of Ladysmith', 'Transvaal', 'Laing's Nek', awarded to Colonel William Henry Slingsby O'Neill, The Royal Dublin Fusiliers

Circular, silver campaign medal with, on the obverse, a profile head of Queen Victoria with the inscription, 'Victoria Regina et Imperatrix' (Victoria, Queen and Empress). On the reverse, the figure of Britannia holding a Union Flag and laurel wreath, the words 'South Africa', marching troops and warships in the background. The medal is suspended on a red, yellow and dark blue ribbon, with five clasps: 'Tugela Heights', 'Orange Free State', 'Relief of Ladysmith', 'Transvaal', 'Laing's Nek'.

Born on 28 May 1854, O'Neill was commissioned as a lieutenant with the 103rd Foot (Royal Dublin Fusiliers ) on 10 September 1875. He was promoted to captain on 20 January 1884 and major on 16 May 1894. He served in South Africa between 1899 and 1902 and was present at the Relief of Ladysmith, Laings Nek, operations in Orange River Colony and operations in the Transvaal in December 1900. O'Neill also received a Mention in Despatches on 7 February 1901. In November 1902 he became a Lieutenant-Colonel and in 1909 colonel.

The Queen's South Africa Medal was awarded to soldiers who served during the Boer War (1899-1902) in South Africa between 11 October 1899 and 31 May 1902. Twenty-six clasps were awarded with this medal, indicating each action and state campaign of the conflict.