After the end of World War II in Europe, Dempsey was appointed to the command of the British Fourteenth Army and GOC in C Malaya Command and then Land Force Commander, South East Asia. By the time he had arrived however, the war in the East was also over. Within his command were 123,000 British and Dutch prisoners and nearly 750,000 captured Japanese.  Miles Dempsey, although modest and unassuming, was considered to be a highly competent officer. He asserted a very effective control over the British Second Army without taking the limelight. This was despite the stalemate in Normandy and the failure to advance beyond Antwerp and thus ensure that German forces remained isolated. He was claimed by military historian Carlo D'Este to be:  A career infantryman, Dempsey was an ardent student of military history and during the interwar period had frequently visited Europe to study its battlefields firsthand. Blessed with an active and incisive mind, a phenomenal memory and a unique skill in reading maps, Dempsey would soon leave his army staff in awe over his ability to remember everything he saw on a map, to bring a landscape literally to life in his mind even though he had never actually seen it. This talent proved particularly important during the crucial battles around Caen in June and July 1944. Dempsey was considered the Eighth Army's best expert in combined operations and, as he grew in experience, Montgomery soon recognized his potential for army command. The two men shared many qualities, including a disdain for paperwork and a determination, based on their First World War experiences, never to waste their soldiers lives.

Answer this question "What did dempsey study?" by extracting the answer from the text above.
After the end of World War II in Europe, Dempsey was appointed to the command of the British Fourteenth Army and GOC in C Malaya Command