As Jersey was loyal to the English Crown but only 14 miles from the coast of France, fear of French invasion was a constant concern to the islanders over the centuries during which England and France were at war. In 1779 there was an unsucessful French attack in St Ouen’s Bay and two years later they briefly took the capital, St. Helier.
The Governor of Jersey, General Conway, decided to build 32 round towers to protect the island's coastline. It would take the British Navy a further 16 years to realize the value of such fortifications and begin to construct the Martello Towers along the coast of Kent. Kempt Tower was built in 1834, its date stone can be seen above the door, in St Ouen’s Bay on the west coast of Jersey. Constructed with Jersey granite, the ground floor was used to store weapons and ammunition whilst the upper floor housed ten troops and their commanding officer. A cannon was fixed to a rotating platform on the roof. It is a Martello Tower and the only one of its kind surviving in Jersey.
All of the other towers on the island are of a slightly different design and even though they are all commonly referred to as Martello Towers this is incorrect, a Martello Tower is a tower built after 1794 and has a battery on top. During Summer months the tower is home to an exhibition on the adjacent Les Mielles conservation area.