In the late 1770s, when the Virgin Islands were still under Danish rule, Lt. Peter Lotharius Oxholm scouted out several locations on Hassel Island that would be key points for defensive fortifications. His suggestions for strategic positions included the North and South peaks of the island along with a site on the southeast coast where Prince Frederik’s Battery was constructed.
In 1801, the British began their occupation of the Danish West Indies during the French Revolutionary War. Lt. General Thomas Trigge ordered forces to fortify Hassel Island for the occupation. Lt. Col. Charles Shipley planned the new defensive constructions necessary for the occupation. Utilizing the same locations that Oxholm named twenty years earlier, the British erected Shipley’s Battery on the northern peak of Hassel Island.
Shipley’s Battery commanded the western approaches via the Gregerie Channel. The semi-circular layout allowed for defensive views of the waters and embrasures for weapons. Despite the drawing above, explained below, the battery was designed to house 5 cannons, and included portable magazines. The remains of a guardhouse are located slightly east of the main structure. After the end of the second British occupation and conclusion of the Napoleonic Wars in the Danish West Indies in 1815, the guardhouse was transformed into a smallpox hospital.