I muri i tana wehenga atu i Gordonstoun i te timatanga o te tau 1939, ka oti i a Philip tetahi wa hei kaiako i te Royal Naval College, Dartmouth, ka hoki mai ki Kariki, e noho ana me tona whaea i Athens mo te marama i waenganui o te tau 1939. I runga i te tono a te kingi Kariki, George II (tona whanaunga matua), ka hoki ia ki Ingarangi i te marama o Hepetema ki te whakahou i te whakangungu mo te Royal Navy. I puta ia i Dartmouth i te tau e whai ake nei hei kaiako pai rawa atu i tana akoranga. I te Pakanga Tuarua o te Ao, i haere tonu ia ki te mahi i roto i nga ope o Ingarangi, i te wa e rua o ona taina, Prince Christoph o Hesse me Berthold, Margrave o Baden, i whawhai i te taha Tiamana. I tohua a Philip hei kaitiaki i te marama o Hanuere 1940. E wha marama i noho ai ia ki runga i te kaipuke whawhai, e tiaki ana i nga waka o te Australian Expeditionary Force i te Moana Nui o Inia, i whai ake i nga pou poto i runga i, i runga i, me te Ceylon o Ingarangi. I muri i te whakaekenga o Kariki e Itari
I te Oketopa 1940, i whakawhitihia ia mai i te Moana-a-Kiwa ki te kaipuke whawhai i te Mediterranean Fleet.