Falmouth Harbour on the south west coast has been fortified since the Iron Age. The first artillery fortifications were St Mawes and Pendennis Castles built by Henry VII by 1545. Over the next centuries fortifications were built at Pendennis Head, around St Mawes and also St Anthony Head.
Building of a new battery at Pendennis Point was stopped in 1846 but in 1852 both Pendennis and St Mawes batteries were re-armed with new artillery.
By 1865 a graving dock had been built at Falmouth.
In 1889 a submarine mine field was deployed to cover the harbour, complete with observation posts, defence electric lights and quick fire gun batteries.
In 1895 6-inch BL guns on HP mounting were built at Pendennis and two 6-inch BL guns at St Anthony Head.
In 1901 new barracks were built at Pendennis, and by 1902 a regiment of artillery was in residence.
Designed at as a Class C Harbour, by the Home Ports Defence Committee, later the Home Defence Committee with defences designed to resists attack by unarmoured cruisers and block ships.
By 1900 there were two principal batteries:
- Half Moon Battery (adjacent to Pendennis Castle) which was built between 1894 and 1897 with two 6-inch disappearing guns. These two guns were upgraded to 6-inch Mark VII between 1909 and 1911. There was also Quick Fire Batteries around Pendennis Castle.
- St Anthony Battery built between 1895 and 1897 and then refurbished between 1903 and 1904 to mount two 6-inch Mark VII guns.