Michael Adler

Michael Adler DSO, SCF (27 July 1868 – 30 September 1944) was an English Orthodox rabbi, an Anglo-Jewish historian and author who was the first Jewish military chaplain to the British Army to serve in time of war, serving with the British Expeditionary Force on the Western Front during the First World War from 1915 to 1918. He was responsible for the Magen David being carved on the headstones of Jewish soldiers who died in wartime instead of the traditional Cross.

https://en.wikipedia.org/wiki/Michael_Adler