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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5. The beginning of the Second World War in Portsmouth
In the summer of 1942 the Portsmouth City Police paraded on the square of the Victoria Barracks, Southsea. Photo: The News archive
6. The beginning of the Second World War in Portsmouth
circa 1940: Citizens of Portsmouth trying to find sleeping accommodation in the nearby countryside, after severe bombing raids on their city. (Photo by Keystone/Getty Images) Photo: The News archive
7. The beginning of the Second World War in Portsmouth
The remains of Stanley Street, Portsmouth, after the third air raid on the city - August 24, 1940 Photo: The News archive
8. The beginning of the Second World War in Portsmouth
The 214 Battery during the units time on Southsea Common. Photo: The News archive