Jersey has a wide range of defensive fortifications dating from prehistoric times through to the 1940s. St Ouen’s Bay is one of the most exposed stretches of coast in Jersey and was historically vulnerable to invasion. The 18th century witnessed a period of increased political tension between Britain and France and because of its geographical location Jersey was more or less on a continuous war footing. King William IV enquired as to the state of Jersey’s coastal defences in 1831 and a report was commissioned from Lieutenant-Colonel Lewis, the Commanding Engineer in Jersey. It was found that new measures would be necessary alongside a chain of batteries and coastal defence towers (known as Conway towers), which already existed in locations along St Ouen’s Bay.
The States of Jersey ordered that work commence on the construction of new coastal defences on 3rd March 1832 and a series of towers of the English Martello pattern was built. Following a dispute in the local court for the ownership of the land, the Tower was completed in 1835 at a cost of £798.00. As part of the western coastal defences, Lewis’s Tower housed one heavy gun, an officer and 18 men with a magazine capable of containing 90 barrels of powder. In 1839, the outside of the Tower was coated in cement due to a report in which it was considered damp and needed to be made weather-tight.
By 1922, after some years of neglect, Lewis’s Tower was sold privately by the War Department to the States of Jersey. During the German Occupation of Jersey, 1940–1945, Lewis’s Tower was requisitioned. A concrete housing was added to the base of the Tower for a mobile 3.7 cm anti-tank gun and a new entrance door created at ground level. Following the end of the Occupation, Lewis’s Tower was transferred in ownership to the Public of the Island of Jersey and opened as a self-catering let in 2007.