Military use of Cape Peron commenced in 1916, when the Commonwealth of Australia acquired 175 hectare on the peninsular from the Western Australian State Government.
The land was purchased as part of a plan to make it part of the Henderson Naval Base, whose construction had been started in 1913, but these plans were never carried out.

As early as 1921 it was suggested by The West Australian newspaper that the defence of Fremantle Harbour required the fortification of key points on Garden Island, Rottnest Island and Cape Peron.
Instead, the Cape became a popular tourist destination and the Australian Government even offered to lease the area to the Rockingham Road Board, a forerunner of the City of Rockingham, in 1934.
Cape Peron was however still occasionally used by the military for training exercises.

During the mid-1930s, the Australian Government upgraded its coastal defence batteries protecting the major ports of the country from enemy attack.
In Western Australia, protection of the Fremantle Port was a priority.
This was to be achieved by upgrading existing batteries and constructing new ones.
At Buckland Hill, Swanbourne, North Mole, Arthur Head, South Beach, Point Peron, Garden Island and Rottnest Island, batteries were either upgraded or new batteries were to be installed.

These combined coastal defences were referred to as the Fremantle Fortress.
Originally, the defence of the port was to be achieved through the placement of 9.2-inch naval guns at Buckland Hill but this was deemed insufficient to protect the port from long range bombardment by cruisers equipped with 8-inch guns.
Instead, the 9.2-inch guns were placed on Rottnest Island as part of the Oliver Hill Battery, which allowed engagement of enemy ships before they reached a range where they could fire at Fremantle Port, having a range of 28 kilometre.
The defence of Fremantle Port was deemed essential to national Australian security during a potential future war.

Additional batteries, equipped with 6-inch Mk VII naval guns and 6-inch Mk XI naval guns, were installed at Rottnest Island (the Bickley Battery), and at Fort Forrest, North Fremantle.
The Fort Forrest guns were moved to Swanbourne in 1938, with Buckland Hill not selected at this point because of its proximity to vital other installations.
At the start of World War II, both of the batteries at Rottnest Island and the Arthur Head and Swanbourne ones were operational.

After the Fall of Singapore and the Bombing of Darwin in February 1942, Fremantle's importance increased, becoming the largest submarine base in the Southern Hemisphere.
Military use of Cape Peron commenced in 1916, when the Commonwealth of Australia acquired 175 hectare on the peninsular from the Western Australian State Government. The land was purchased as part of a plan to make it part of the Henderson Naval Base, whose construction had been started in 1913, but these plans were never carried out.
As early as 1921 it was suggested by The West Australian newspaper that the defence of Fremantle Harbour required the fortification of key points on Garden Island, Rottnest Island and Cape Peron. Instead, the Cape became a popular tourist destination and the Australian Government even offered to lease the area to the Rockingham Road Board, a forerunner of the City of Rockingham, in 1934. Cape Peron was however still occasionally used by the military for training exercises.
During the mid-1930s, the Australian Government upgraded its coastal defence batteries protecting the major ports of the country from enemy attack. In Western Australia, protection of the Fremantle Port was a priority. This was to be achieved by upgrading existing batteries and constructing new ones. At Buckland Hill, Swanbourne, North Mole, Arthur Head, South Beach, Point Peron, Garden Island and Rottnest Island, batteries were either upgraded or new batteries were to be installed.
These combined coastal defences were referred to as the Fremantle Fortress. Originally, the defence of the port was to be achieved through the placement of 9.2-inch naval guns at Buckland Hill but this was deemed insufficient to protect the port from long range bombardment by cruisers equipped with 8-inch guns. Instead, the 9.2-inch guns were placed on Rottnest Island as part of the Oliver Hill Battery, which allowed engagement of enemy ships before they reached a range where they could fire at Fremantle Port, having a range of 28 kilometre. The defence of Fremantle Port was deemed essential to national Australian security during a potential future war.
Additional batteries, equipped with 6-inch Mk VII naval guns and 6-inch Mk XI naval guns, were installed at Rottnest Island (the Bickley Battery), and at Fort Forrest, North Fremantle. The Fort Forrest guns were moved to Swanbourne in 1938, with Buckland Hill not selected at this point because of its proximity to vital other installations. At the start of World War II, both of the batteries at Rottnest Island and the Arthur Head and Swanbourne ones were operational.
After the Fall of Singapore and the Bombing of Darwin in February 1942, Fremantle's importance increased, becoming the largest submarine base in the Southern Hemisphere.
Peron Battery