Sydney Crookshank

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File:Le général Crookshank, visite de la British legion au cimetière de Notre-Dame de Lorette, le 7 août 1928 (cropped).jpg

Major-General Sir Sydney D'Aguilar Crookshank {{post-nominals|country=GBR|size=100%|KCMG|CB|CIE|DSO|MVO}} (3 June 1870 – 17 August 1941) was a British military engineer who served with the Royal Engineers in the British Army and the British Indian Army. Most of his early career was spent in colonial service; he later served as a senior officer during the First World War.'CROOKSHANK, Maj.-Gen. Sir Sydney D'Aguilar', at Who was Who.

As a temporary lieutenant colonel he was Commander, Royal Engineers (CRE), of 47th (1/2nd London) Division on the Western Front from 30 July 1915 to 27 November 1916.Becke, Pt 2a, p. 69.Edwards, Appendix G.Maude, Appendix D. On 21 May 1916 in the Vimy sector the Germans fired a mine and attacked the division's positions in overwhelming numbers. The situation was so critical for a while that Crookshank brought his Sappers of 47th (2nd London) Divisional Engineers up to man the trenches as infantry.Edmonds, pp. 216–8.Maude, pp. 54–5. He was awarded a Distinguished Service Order on 3 June 1916.[https://www.thegazette.co.uk/Edinburgh/issue/12947/page/993 Edinburgh Gazette, 5 June 1916.] In January 1917 he was promoted to the temporary rank of brigadier general and made a chief engineer{{London Gazette|issue=29996|page=2861|date=23 March 1917}} of XV Corps.https://livesofthefirstworldwar.iwm.org.uk/story/72901

Later, as a major general he was appointed Director-General (Transportation) of the British Armies in France on 19 March 1918.Becke, Pt 4, p. 12.

After the war, Crookshank was appointed Honorary Colonel of 47th (2nd London) Divisional Engineers on 3 March 1923.Edwards, Appendix F.Monthly Army List.

In February 1936 he succeeded Lieutenant General Sir George Fowke as colonel commandant of the Royal Engineers.{{London Gazette|issue=34258|page=1164|date=21 February 1936}}