Hackness Battery was originally known as Fort George and Long Hope Battery. The Battery was built between 1813 and 1814, at the same time as the adjacent Martello Tower. The Battery originally mounted eight 24-pdr SB guns. Hackness Battery has an enclosing wall with a ‘V’ shaped coastal battery. A defensible barracks protected the gorge of the battery, and the main magazine was inland from the barracks, surrounded by earthen blast walls. A guard house and officers quarters were located at the main gate.
In 1866 the battery was upgraded to mount four 68-pdr RML guns. The old 24-pdr on the top of the Hackness Martello Tower was also replaced with a 68-pdr RML. This upgrade was primarily due to the assumed risk from the American Fenian Brotherhood.
The Battery was later used primarily for training of the Orkney Artillery Volunteers. In 1883 the battery had two artillerymen on site.
1914 to 1918 the Battery was used to house naval personnel who operated the boom defences at this location.
The battery and Martello Tower were decommissioned in about 1900.