Arthur Forbes-Sempill

Rear-Admiral Arthur Lionel Ochoncar Forbes-Sempill (1877–1962) was an officer of the Royal Navy active in the First World War.

He was the fourth (and youngest) son of William Forbes-Sempill, 17th Lord Sempill; his three elder brothers, John, Douglas and Robert, all served in the Army.

In January 1898, he was assigned to HMS Centurion as a sub-lieutenant, promoted to Lieutenant on 30 June of the following year, and then assigned to HMS Victorious. In 1900 he was assigned to HMS Vernon for torpedo training, in July 1902 posted to HMS Empress of India., in December 1903 to HMS Euryalus, in May 1906 to HMS Edgar, in September 1908 to HMS Bacchante, and in May 1910 to HMS King Alfred. He was then promoted Commander, and assigned to HMS Albemarle in 1911.

In July 1914 he was assigned to HMS Dominion, in which he served during the early part of the First World War. He was later posted as executive officer of the battleship HMS Valiant (1914), where he saw service at the Battle of Jutland, and was recommended for promotion to Captain as a result. He later commanded the cruisers HMS Blonde and HMS Cordelia, and was present in the latter at the surrender of the German navy in 1918. By 1919, he was in command of HMS Colossus.

He married in 1903, and was divorced in July 1914, on the grounds of adultery; the case was not defended. He remarried in 1919, to Helen Allen; she died shortly thereafter, in 1921. He remarried for a third time in 1926, to Mary Holland, an American. He had one daughter from his second marriage, Janet, and one son by his third marriage, John, who would later inherit the baronetcy held by Arthur's father, after it had passed through his elder brother William and his nephew Ewan.