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.
You can subscribe here for unlimited access to Portsmouth news online - as well as our new Puzzles section.
9. The beginning of the Second World War in Portsmouth
The King inspects members of the Local Defence Volunteers during a visit to Portsmouth on July 25, 1940 Photo: The News archive
10. The beginning of the Second World War in Portsmouth
The original floral clock in Southsea about 1940. England Expects That Every Man This Day Will Do His Duty. Photo: The News archive
11. The beginning of the Second World War in Portsmouth
Winston Churchill at the beginning of the war. Photo: The News archive
12. The beginning of the Second World War in Portsmouth
Here we see Highbury Buildings south of Cosham railway gates after being hit on December 12 1940. Two local people were killed by this explosion. Joan Millet aged 19 of Chatsworth Avenue, Highbury and Frederick Waldron aged 53 of Park Grove, Cosham. Photo: The News archive