During the Second World War, East Kent was at the forefront of the defence of the United Kingdom. In 1940 the ports of Dover, Ramsgate, Folkestone and Margate took part in the Dunkirk evacuation, while airfields such as Manston, Hawkinge and Lympne were active in refuelling aircraft involved in the Battle of Britain.

It was also from Dover that the first steps for D-Day were initiated, with commando raids on French beaches from Royal Navy motor launches. German signals were monitored and subsequently jammed by a series of experimental units. Balloons launched from Kingsdown carried leaflets to enemy territory, while others defended harbours and factories from dive bombers.

Throughout the remainder of the war, including the defence against the V1 flying bomb attacks of the summer of 1944 and the supply of both men and material to the allies as they advanced through Europe, East Kent played a vital role.