John Forbes Sempill, 18th Lord Sempill

John Forbes-Sempill, 18th Lord Sempill (21 August 1863 – 28 February 1934) was a Scottish peer, the 18th Lord Sempill and 9th Baronet of Craigievar.

He was the son of William Forbes-Sempill, 17th Lord Sempill, and Frances Emily Abercromby, the daughter of Sir Robert Abercromby, 5th Baronet, and succeeded to the titles on the death of his father in 1905, prior to which he was known by the courtesy title "Master of Sempill". In addition to three sisters, he was the eldest of four brothers, all of whom served in the military; Douglas, a Major in the Seaforth Highlanders, was killed on the North-West Frontier of India in 1908, whilst Robert was killed in the Battle of the Somme serving with the Gordon Highlanders. The youngest of the four, Arthur, was in the Royal Navy, and survived the Battle of Jutland. A fifth brother, William, died in infancy.

After studying at Eton, he joined the 3rd (Militia) Battalion of the Gordon Highlanders in 1883, then transferred to the Queen's Own Cameron Highlanders in 1885. After service in the Sudan, he transferred to the Army Service Corps in 1894, then transferred into the Black Watch in 1894. He served with the Lovat Scouts and then the Black Watch in the Second Boer War, and only left South Africa after the end of the war, in late July 1902. He would later go on to command the 8th Battalion Black Watch in the First World War, where he was severely wounded at the Battle of Loos and mentioned in despatches. He later claimed to have been the first man from Kitchener's Army to land in France; he had leapt ashore before the troopship had tied up at the dock. He later served in the House of Lords as a Scottish representative peer, and was later the chairman of the Aberdeenshire Territorial Army Association, the Honorary Colonel of the 5th Battalion Gordon Highlanders - his brother Robert's battalion - and an aide-de-camp to King George V.

His wife, Gwendolyn Prodger, was born and raised in Wales, with a Cornish mother, and was an accomplished harpist. The two had met at the fashionable resort of Homburg in the 1880s, and were married on 22 June 1892.

They had three children; the eldest, William, who led a trade mission to Japan and then through his anti-semitic beliefs sold British aviation secrets to the Japanese, succeeded to his father's titles. The baronetcy would later pass to their younger son, Ewan, on William's death, whilst the barony passed to their granddaughter Ann. In addition to the sons, they had two daughters; Gwendolyn (also known as Gwyneth), who died of appendicitis aged twelve, and Margaret, who later became a Justice of the Peace and a decorated member of the Women's Auxiliary Air Force in the Second World War.