Ewen George Sinclair-MacLagan was born in Edinburgh, Scotland on 24 December 1868 to the banker Robert Ewen Sinclair-Maclagan and his wife Mary Alice Wall. He attended the United Services College in North Devon, England, where Rudyard Kipling was one of his classmates.[1]
In 1901, Sinclair-MacLagan was seconded to the Australian Army and served as adjutant of the New South Wales Scottish Rifles. After three years in Australia, he returned to his regiment in England. In 1910, he was a major and serving with the Yorkshire Regiment when the then Brigadier William Bridges, who knew Sinclair-MacLagan from his time in Australia, offered him a position as a drill instructor at the newly established Royal Military College at Duntroon. Sinclair-MacLagan accepted the position and returned to Australia as a lieutenant colonel.[1]
First World War
Upon the outbreak of the First World War in August 1914, Bridges was instructed to form the Australian Imperial Force (AIF) for service overseas. He selected Sinclair-MacLagan to be the commander of 3rd Brigade, 1st Division. Sinclair-MacLagan was the only brigade commander of the division to be a professional soldier.[4] He oversaw the training of the brigade, most of whom were miners, in the Middle East.[5]
Gallipoli
Sinclair-MacLagan's brigade was selected to be the lead element of the division when it landed at Gallipoli on 25 April 1915.[1] On reaching the high ground at Plugge's Plateau, he quickly realised that his brigade had been landed in the wrong position. Making the best of a confusing situation, he directed his forces to secure Baby 700, a prominent feature overlooking the ANZAC positions.[6] This could not be done, and he opted to establish positions on what would become known as the Second Ridge.[7] Exhausted after dealing with Turkish counterattacks the following day, he was relieved of his command.[8] After a period of rest, Sinclair-MacLagan returned to his brigade but was medically evacuated in August. He was promoted to temporary brigadier general around this time, dated back to 15 August 1914.[9] He resumed command of the brigade in January 1916, at which stage it was reforming in Egypt after being evacuated from Gallipoli.[1]
Western Front
The 3rd Brigade, with Sinclair-MacLagan still in command, participated in the Battles of Pozières and Mouquet Farm from July to September 1916. He left his brigade in December 1916 to become commander of the AIF depots in England.[1] He was appointed a Companion of the Order of the Bath in February 1917 for his war service to date.[10] He returned to the Western Front in July 1917 when the commander of the 4th Division, Major General William Holmes, was killed shortly after the Battle of Messines. Sinclair-MacLagan was to take over command of the division, which he would lead for the remainder of the war.[1]
Promoted to temporary major general, Sinclair-MacLagan had little opportunity to stamp his mark on the division before the upcoming Battle of Passchendaele, but it performed well in the Battle of Polygon Wood. Its next major engagement was in March 1918 when it was rushed to the Somme sector to counter the German spring offensive.[1] It took up positions on the Ancre and rebuffed several attempts by the Germans to break through.[11] In September, the 4th Division relieved the 5th Division in the line and participated in the attacks on the Hindenburg Line.[12] He also led the Australian mission that assisted in the training of the II American Corps, American Expeditionary Forces (AEF), prior to its participation in the successful Battle of St. Quentin Canal.[1]
Sinclair-MacLagan returned to duty with the British Army and served as commander of the 51st Highland Division before retiring in 1925. He retained a connection to the Australian Army through his honorary colonelcy of the 34th Battalion. He was also colonel of the Border Regiment from 1923 to 1936. He died in Dundee, Scotland on 24 November 1948. He was survived by his daughter, the only child of his marriage to Edith Kathleen French, the daughter of George Arthur French. His wife had died in 1928.[1]
Pedersen, Peter (2011). ANZACs on the Western Front: The Australian War Memorial Battlefield Guide. Milton, Queensland: John Wiley & Sons. ISBN978-1-74216-981-1.