Discovered by the Portuguese navigators on Saint Thomas Day in 1470, the first settlement was established only several years later, in 1493. Most of the early settlers were jews, orphans or criminals sent from Portugal. With the help of slave labour from the African mainland, the settlers transformed the fertile volcanic soil into the world’s biggest sugar producing plantations.

After the slave revolt in 1595, led by national hero King Amador, many plantation owners became frightened by the insecurity and retreated to Brazil. Sugar cultivation thus declined over the next 100 years, and by the mid-1600s the economy had changed. It was now primarily a transit point for ships engaged in the slave trade between the West and continental Africa. In the early 1800s, coffee and cacao plantations “roças” were developed on the rich volcanic soils owned by Portuguese companies and absentee landlords. By 1908, Sao Tome had become the world’s largest producer of cacao with an exotic sobriquet, "The Chocolate Islands".

The roças system was abusive toward African farm workers even after slavery was abolished in 1875. If the islands’ plantations were shorthanded, Portugal imported indentured workers from Cape Verde, Angola, and Mozambique to fill in. In 1909 the international community decided to end these practices by boycotting the islands’ products, which led to a crash in the cacao trade. The fall of the fascist government in Portugal in 1974 signalled the end of Portuguese colonial rule. Sao Tome and Principe achieved independence on 12th July. In 1990, Sao Tome became one of the first African countries to embrace democratic reform.