The Moors, who occupied Gibraltar for 727 years and the Spaniards, who stayed for 266 years, were awake to the strategic importance of Parson's Lodge. The former built a wall shortly after 1333 and the latter improved it and recorded it in 1627.

When the British arrived in 1704 it was clearly necessary to protect the anchorage immediately north of Parson's Lodge.

The armament list of 1720 records four guns at Rosia (sic) 2x18 pounders and 2x12 pounders. By 1744 this had risen to 19 guns in Rosia and two, to the South, in Camp Bay. The name Parson's Lodge first appears in writing, in 1761, in a book in the Garrison Library. By 1771 it appeared, by name, in the armaments list. This name seems to be an irreverent reference to the hermitage and chapel of St. John the Green, situated immediately landward of Parson's Lodge Rock.

By the end of the nineteenth century Parson's Lodge was fast becoming a self-sufficient coastal artillery searchlight position - with its own generating facility. However, infantry and artillery returned in the two Great Wars and a further spate of building was undertaken by the second Btn. Somerset Light Infantry, in 1941, to accommodate anti-tank guns, anti-aircraft guns and anti-aircraft searchlights. The site was abandoned by the military in about 1956 and has been used for training exercises spasmodically ever since.