Fremantle Harbour serves the large Port of Perth and became a major hub in the 1880s with the discovery of gold in the hinterland. The inner harbour was only built in 1897 and it was only after that had been completed that a single coastal defence battery was built in 1906 at Fort Arthur Head. This battery was armed with two 6-inch Mark VII guns. In 1911 plans were advanced for building a major naval base at Freemantle, the Henderson Naval Base, but the work floundered with the advent of World War I.
It was during World War 2 that Freemantle was heavily fortified with ten additional coastal defence batteries. These were: