As these historic photos show, the early months of the war meant residents had to quickly train as soldiers before departing for Europe and leaving their loved ones behind.
In our gallery you will also see young evacuees leaving the city and residents of Goodwood Road about to embark on an outing not realising that in two months time the country would be at war. You will also see some of the first areas to be hit by the air raids and the devastation of those bombs.
MORE RETRO PHOTOS: Portsmouth 70 years ago | The oldest places in Portsmouth | Lost Portsmouth shops
Most of the area in Portsmouth destroyed in air raids has now been rebuilt, but the memories of the devastating war still remain.
More photos from this collection can be found on our new Facebook group Portsmouth Retro – you can join here.
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17. The beginning of the Second World War in Portsmouth
Evacuee family September 1939. The News PP296 Photo: The News archive
18. The beginning of the Second World War in Portsmouth
On February 25, 1940, the Home Secretary Sir John Anderson paid us a visit. Photo: The News archive
19. The beginning of the Second World War in Portsmouth
15th October 1939: Anxious relatives read a list of survivors from the HMS 'Royal Oak' posted up at a South Coast Port. The Admiralty states that battleship was sunk by a U-boat. (Photo by E. Phillips/Fox Photos/Getty Images) Photo: The News archive
20. The beginning of the Second World War in Portsmouth
Children wave goodbye to Portsmouth September 1939. The News PP308 Photo: The News archive