Ya shafe mafi yawan yakin a kan wasu alƙawari na ma'aikata, kuma ya auri Victoire Marion Williams-Freeman a 1942. An ba shi mukamin Laftanar Kanal, an nada shi a matsayin Kwamandan Kwamandan (CO) na 1st Battalion, Manchester Regiment, a watan Maris na 1944. Bataliya (a baya bataliya ta 6, rundunar sojojin kasa kafin a sake sanya ta a matsayin bataliya ta 1 a watan Mayu na shekarar 1942), tana aiki a matsayin bataliya mai dauke da bindigogi na 53rd (Welsh) Infantry Division, wani rukunin farko na TA wanda Manjo Janar Robert Ross ya ba da umarni, ba shi da horo sosai kuma kusan bai dace da aiki ba, amma Harington da sauri ya kawo shi cikin cikakken shiri. Rundunar ta, tare da mahaifiyarta, ta sauka a Normandy, Faransa, a karshen watan Yuni, makonni uku bayan da aka sauka a Normandy, kuma an yi ta fama da mummunan fada a duk lokacin yakin Normandy, kuma mafi yawan wadanda suka biyo baya.
Harington ya yi watsi da umurnin a tsakiyar watan Satumbar 1944, lokacin da ya zama Babban Jami'in Janar na Grade 1 (GSO1) tare da HQ na 53rd Division. Ya ci gaba da wannan mukamin har zuwa Mayu 1945. Domin ayyukansa a matsayin CO na 1st Manchesters, Harington ya ba da lambar yabo ta DSO a farkon 1945.