WWII Australian-British military mail in Palestine / 'Horseshoe Route': 15 SE 1940 airmailed green honour envelope from FPO 122 (TULKARM) to EDINBURGH Scotland, franked 1s/3d at period 'hourshoe route' rate, using British stamps & tied by 2 strikes of FPO postmark; return addressed to soldier of D Troop, 4th Battery, 2/2 Field Regiment, 6th Division of 2nd Australian Imperial Force (AIF - the volunteer component of the wartime Australian Army; not recorded as serving in Palestine but the 6th Division fought in the Western Desert Campaign at Bardia, Tobruk & Benghazi) - unusual as military mail normally sent without displayed return address. Passed censor #224 in Palestine. This special rate was in use locally from Sept. - Nov. 1940; mail was sent by air via TIBERIAS or CAIRO to DURBAN South Africa, and then by sea to UK: here probably on flight WS16 departing SYDNEY on 11 SEPT, reaching TIBERIAS/CAIRO on 19-20th & DURBAN on the 23rd. Slit open at top. Rare origin & scarce route.