William Galbraith King was the youngest son of David King, J.P., Tigh-Ruadh, Possilpark (Messrs David King & Sons Ltd, Keppoch Iron Works).

In 1901, the King family were living at 4 Viewmount Drive, Maryhill, Lanarkshire: Father, David (Iron Founder) (45); Mother, Jessie Richmond (37); Daughter, Mary R. (15); Son, David Hutton (13); Son, John (11); Daughter, Jessie McMillan (8); Son, William Galbraith (4); and Daughter, Charlotte, Kellan (10 months). Also living at this address was Mary Mathieson (Domestic Servant) (24). 

He was educated at Perth Academy and Glasgow High School, where he developed a considerable athletic talent. He was especially keen on rugby, and played for the school First XV in the 1913-1914 season, earning his cap. 

William King was an enthusiastic Scout with the 1st Glasgow Troop, and joined the University Officer Training Corps when he went up to study Medicine at the University of Glasgow in 1914. He enrolled for classes in Zoology and Chemistry, but had no time to test his academic mettle before war broke out and he was gazetted to the 8th Royal Scots Fusiliers in January 1915.

After excellent service in the early days at Maryhill Barracks, William King was posted abroad with the 8th Royal Scots Fusiliers. Early in November 1915 he was attached to the 1st Royal Munster Fusiliers and sailed for Gallipoli. He took part in both evacuations, at Suvla and Cape Helles.

Afterwards he saw service in Egypt (Suez and the Sinai desert). Leaving Egypt with his Division (29th), he next saw service on the Western Front. On 25th April 1916 the 1st Royal Munster Fusiliers joined the 48th Brigade, 16th (Irish) Division in the Somme region.

The Somme offensive began on 1st July 1916, with the Battle of Albert which continued until 13th July. While there is no definitive record of where William King lost his life, it is known that on 6th July 1916, at some stage of the Battle of Albert, he was killed instantaneously while speaking to a wounded man. He was nineteen years old.

William King is also commemorated on the High School of Glasgow War Memorial; and the University of Glasgow Roll of Honour.