With the Napoleonic Wars in full swing, British and Scandinavian merchant shipping transiting the lucrative trade route around Orkney were often attacked by French and American privateers. The Hackness Battery and two Martello Towers were built in 1813–14 to help protect the safe anchorage at nearby Longhope Sound. Their guns were never fired in anger. 

In 1866, the battery and towers were upgraded with new artillery and barracks in response to an emerging threat from the American Fenian Brotherhood. Once again, it never saw enemy action. Indeed, the only record of the guns ever being fired is in 1892, during a day of drill and target practice for the Orkney Volunteer Artillery.