[2] He was the son of John Juchereau Kingsmill, Crown Attorney for Wellington County, and Ellen Diana Grange.

[4] During his career in the Royal Navy, he commanded HM Ships Goldfinch (1890–1891), Blenheim (1895), Archer (1895–1898), Gibraltar (1900), Mildura (1900–1903), Resolution, Majestic (1905–1906), and Dominion.

During Kingsmill's command of the ship, she was part of the naval escort for the visit of the Duke and Duchess of Cornwall and York (later King George V and Queen Mary) to New Zealand aboard the chartered Royal liner HMS Ophir during 1901.

In his March 1907 court-martial, Kingsmill was severely reprimanded for "grave neglect of duty" (not being on the bridge at the time) and given command of the older battleship HMS Repulse.

[13][14] By 1914, at the beginning of World War I, the new navy's fleet consisted of two old cruisers and a collection of converted civilian and commercial vessels.

He maintained a summer home on Grindstone Island, in Big Rideau Lake, near Portland, Ontario, where he loved to sail.

His guests included the Duke of Devonshire, Governor General of Canada from 1916 to 1921; Sir William MacKenzie, railway entrepreneur; and Neville Chamberlain, later Prime Minister of the United Kingdom from 1937–1940.