In a move towards Federation the Australian colonies agreed in 1890 that the defence of naval coaling stations at Thursday Island and Albany (Western Australia) should be undertaken collectively.

In 1891 a colonial defence committee recommended that three 6-inch guns that had been offered by the British government should be emplaced at Green Hill on Thursday Island.

Costs of construction were shared between the colonies with Queensland providing a permanent garrison of 50 men. Clearing and excavating of the site on Green Hill began in August 1891 and the battery, named Fort Victoria, was ready to receive the guns by 1893. In 1897 a 4.7-inch gun was added at Milman Hill.

Rapid changes in European military and naval technology made Fort Victoria obsolete from its inception, but the installation remained operational until the garrison was moved to Darwin in 1932.

Prior to Japan’s entry into World War II, it had been recognised by Australian defence authorities that the Torres Strait Islands could provide potential operational bases for foreign forces approaching from the north and in early 1940 it was decided to establish a system of seaward fortifications. In May 1940 the Australian Defence Committee asked for recommendations on the most appropriate site for mounting two 6-inch naval guns for Torres Strait. A recommendation was made to install the guns at Tucker Point on Goods Island from where they could cover the Prince of Wales Channel and Normanby Sound as well as the eastern and western approaches to Thursday Island and the airfield on Horn Island. It was also recommended that the 4.7-inch gun be re-instated at Milman Hill on Thursday Island. The main role of Thursday Island was as an administrative base for Torres Strait Force. The role of the troops on the island was the denial to the Japanese of the sea channels covered by the Milman Battery and the defence of the military installations on the island.

Today the World War II Battery Observation Post (BOP) on top of Milman Hill is fenced within a more recent transmission facility. The BOP is of reinforced concrete with a ground-level observation post and below-ground control centre. Two reinforced concrete searchlight posts-each with its generator shed-are located below, facing towards Horn Island. One is now locally known as Lions Lookout.