Occupied at various times by the Khmer, Malays and Vietnamese, Con Son Island also served as an early base for European commercial ventures in the region. The first recorded European arrival was a ship of Portuguese mariners in 1560. The British East India Company maintained a fortified trading post here from 1702 to 1705 – an experiment that ended when the English on the island were massacred in a revolt by the Makassar soldiers they had recruited on the Indonesian island of Sulawesi.
Con Son Island has a strong political and cultural history, and an all-star line-up of Vietnamese revolutionary heroes were incarcerated here. (Many streets are named after them.) Under the French, Con Son was used as a major prison for opponents of colonialism, earning a reputation for the routine mistreatment and torture of prisoners. National heroine Vo Thi Sau was executed here in 1952.
In 1954, the island was taken over by the South Vietnamese government, which continued to use its remoteness to hold opponents of the government (including students) in horrendous conditions.
During the American War, the South Vietnamese were joined here by US forces. The US built prisons and maintained the notorious 'tiger cages' as late as 1970, when news of their existence was broken by a Life magazine report.
In recent years increasing numbers of settlers from the mainland and a buoyant tourist sector are leading to population pressures.