Pre-1945
In the nineteenth century, the island was considered important because it protected the passage into Keppel Harbour. Plans to fortify the island as part of the defence plan for Singapore were drawn up as early as 1827, but few fortifications actually materialised until the 1880s, when the rapid growth of the harbour led to concern over the protection of coal stocks against enemy attack. The forts built on the island were Fort Siloso, Fort Serapong, Fort Connaught and the Mount Imbiah Battery.
The western end of Pulau Blakang Mati, the place where Fort Siloso is now, used to be called sarang rimau (the tiger's den). Salusuh is a kind of herb used as a remedy in childbirth, but there is no explanation of how the fort came to be so-called, the orang laut of Kampong Kopit only knowing the place by the name of sarang rimau. By the 1930s, the island was heavily fortified and a crucial component of Fortress Singapore, and the base of the Royal Artillery.
During the Second World War, the island was a British military fortress. The British set up artillery guns in Fort Siloso that were then pointed to the south, facing the sea in expectation of a seaward Japanese assault. However, the Japanese eventually invaded and captured Singapore from the north, after having done the same to Malaya (now known as West or Peninsular Malaysia). Following the surrender of the Allied Forces on February 15, 1942, the island became a prisoner of war camp, housing Australian and British prisoners of the Japanese.
During the Japanese Occupation, under the Sook Ching Operation, Chinese men who were suspected, often arbitrarily, of being involved in anti-Japanese activities were brutally killed. The beach at Pulau Blakang Mati was one of the killing fields
1945-1972
After the Japanese surrender in 1945 and the return of Singapore to British rule, the island became the base of the locally enlisted First Singapore Regiment of the Royal Artillery (1st SRRA) in 1947. Other locally enlisted men from Singapore were sent to the island for basic military training before being sent to other units of the British Army in Singapore.
Ten years later, the 1st SRRA was disbanded and its guns dismantled. The coast artillery was replaced with Gurkha infantry units, first the 2/7th Duke of Edinburgh's own Gurkha Rifles and later the 2/10th Princess Mary's own Gurkha Rifles. Fort Siloso and Fort Serapong became a Catholic retreat and a Protestant church house respectively. Fort Connaught was left in ruins.
In the early 1960s, during the Indonesian Confrontation, the 2/10th unit defended the island against Indonesian saboteurs. With the end of the Confrontation in 1966 and the withdrawal of the Gurkha units from the island, the British handed over Sentosa to the Singapore Armed Forces of the newly independent Government of Singapore in 1967.
In 1967, Pulau Blakang Mati became the base for the Singapore Naval Volunteer Force, which relocated there from its old base at Telok Ayer Basin. The School of Maritime Training was also set up there, as was the first Naval Medical Centre.
In the 1970s, the government decided to develop the island into a holiday resort for local visitors and tourists.
1972-Present
The island was renamed “Sentosa” in 1972, which means peace and tranquillity in Malay, from a suggestion by the public.[3] The Sentosa Development Corporation was formed and incorporated on 1 September 1972 to oversee the development of the island.[3] Since then, some S$420 million of private capital and another S$500 million of government funds have been invested to develop the island.[3]
In 1974 the Singapore Cable Car system was built, linking Sentosa to Mount Faber.[5] A series of attractions were subsequently opened for visitors including Fort Siloso, Surrender Chamber wax museum, Musical Fountain, and the Underwater World. The causeway bridge was opened in 1992 connecting Sentosa to the mainland.[5]
The Sentosa Monorail system was opened in 1982 to transport visitors to various stations located around the island.[5] On 16 March 2005, the monorail service was discontinued to make way for the new Sentosa Express, which commenced operations on 15 January 2007.[5] An environmental assessment conducted by the government of Singapore concluded that the construction of the resorts on Sentosa would to result in high likelihood of high scale biodiversity loss, habitat destruction, soil erosion and climate change, as well as several other destructive ecological impacts.[