Ku sii qor faqradan - Dempsey oo ka qalin jabiyay Royal Military College, Sandhurst, 1915 waxaa loo magacaabay taliye labaad ee Royal Berkshire Regiment. Sarkaal yar, wuxuu ku dagaalamay Galbeedka Horteeda intii lagu jiray Dagaalkii Koowaad ee Adduunka, halkaas oo uu ku dhaawacmay, waxaana lagu abaalmariyay Military Cross. Dagaalkii ka dib wuxuu ka soo shaqeeyay Ciraaq intii lagu jiray kacdoonkii Ciraaq ee 1920
, Iran intii lagu jiray dagaalkii sokeeye ee Ruushka, iyo Hindiya.