<prompt> Qedela umusho olandelayo: Ngemva kwempi, uMackay wafunda isayensi yemvelo eNyuvesi yaseCambridge ngaphansi kuka - Ernest Rutherford ngaphambi kokuba abuyele e - Australia nomsebenzi wakhe wakudala njengomfundisi eNyuvesi yaseSydney. Kusukela ngo-1933 kuya ku-1940 wayenguthishanhloko weCranbrook School, eSydney. Wahlala eMilis phakathi kwezimpi, futhi wayengujenene omkhulu ngesikhathi kuqubuka iMpi Yezwe Yesibili. Wakhethwa ukuba ahole i-6th Division ngo-1940, futhi wayihola ngezimpi zokuqala ze-Australian Army zempi. Noma yikuphi ukungabaza ngekhono lakhe ngokushesha kwaphela ngokuzibophezela kwesigaba emkhankasweni wasehlane lasentshonalanga. Phakathi nenkathi  <response>: Impi yaseBardia ngoJanuwari 1941, iDivision 6th yathumba idolobha eliqinisiwe kanye neziboshwa ezingama-36,000 zase-Italy. Empini yaseGreece, waba ukuphela kwesikhulu sase-Australia ukubhekana ne Waffen-SS empini. Wabhekana nokuhluleka okuningi eGrisi, kodwa wahlaba umxhwele amabutho ayewahola ngesibindi sakhe lapho eshaywa. Wabizelwa e-Australia ngo-1941 ukuyokhonza njenge-General Officer Commanding Home Forces. Ngo 6 April 1942, wathatha umyalo we Second Army. Ngo-1943 wahola kabili iNew Guinea Force ekulweni emkhankasweni waseNew Guinea. Inkonzo yakhe esebenzayo yaphela ngokuqokwa kwakhe njengoKhomishana Ophakeme eNdiya ngoNovemba 1943. 