 Commissioned as a second lieutenant into the 1st Battalion of the Duke of Cambridge 's Own ( Middlesex Regiment ) on 8 August 1914 , Horrocks joined the British Expeditionary Force 's retreat following its baptism of fire at the Battle of Mons . On 21 October , at the Battle of Armentières , his platoon was surrounded , and he was wounded and taken prisoner . Incarcerated in a military hospital , he was repeatedly interrogated by his German captors , who believed that the British Army were using expanding bullets in contravention of the 1899 Hague Convention . Horrocks ' captors refused to change his clothes or sheets , and denied him and a fellow officer basic amenities . Both had temporarily lost the use of their legs , and were forced to crawl to the toilet , which caused Horrocks ' wounds to become infected . Conditions improved after his discharge and transfer to a prisoner of war camp . On his way to the camp , Horrocks befriended his German escort — he attributed their rapport to the mutual respect that front @-@ line troops share . He was promoted to lieutenant on 18 December 1914 , despite being in enemy hands , and often tried to escape , once coming within 500 yards ( 460 m ) of the Dutch border before being recaptured . He was eventually placed in a compound for Russian officers , in the hope that the language barrier would hinder his escape attempts ; Horrocks used the time to learn the Russian language . Years later , working in the House of Commons , he surprised Nikita Khrushchev and Nikolai Bulganin by greeting them in their native tongue . In the latter part of the war he was held in Holzminden prisoner @-@ of @-@ war camp . His resistance in captivity would earn him the Military Cross , awarded in 1920 and backdated to 5 May 1919 . 
