The rich volcanic soil and proximity to the equator made São Tomé and Príncipe ideal for sugar cultivation, followed later by cash crops such as coffee and cocoa.

The islands making up São Tomé and Príncipe were formed around approximately 30 million years ago due to volcanic activity in deep water along the Cameroon Line.

Over time, interactions with seawater and periods of eruption have engendered a wide variety of different igneous and volcanic rocks on the islands with complex assemblages of minerals.

In the sugar boom's early stages, property on the islands had little value, with farming for local consumption while the economy relied mainly on the transit of slaves, though already many foodstuffs were imported.

[17] According to Valentim Fernandes around 1506, São Tomé had more sugarcane fields than Madeira "from which they already produce molasses,"[18] but the island lacked facilities for industrial sugar production.

The power dynamics of São Tomé in the 16th century were surprisingly diverse with the participation of free mulatto[s] and black citizens in governance.

Voluntary colonists shunned São Tomé for its disease and food shortages, so the Portuguese crown deported convicts to the island and encouraged interracial relationships to secure the colony.

[31] A formal complaint was lodged by local Portuguese authorities in 1531 lamenting that too many settlers and black citizens were being killed in the attacks, and that the island would be lost if the problem remained unresolved.

[31] A significant event in the maroon fight for freedom occurred in 1549, when two men claiming to be free-born were taken in from the macambos by a wealthy mulatto planter named Ana de Chaves.

[citation needed] Sugar cultivation thus declined over the next 100 years, and by the mid-17th century, São Tomé had become primarily a transit point for ships engaged in the slave trade between continental Africa and the Americas.

[citation needed] The roças system, which gave the plantation managers a high degree of authority, led to abuses against the African farm workers.

[citation needed] Observations of the solar eclipse of 29 May 1919 in Príncipe by Sir Arthur Eddington provided one of the first successful tests of Albert Einstein's general theory of relativity.

In the early 20th century, an internationally publicized controversy arose over charges that Angolan contract workers were being subjected to forced labour and unsatisfactory working conditions.

After a period of transitional government, São Tomé and Príncipe achieved independence on 12 July 1975, choosing as the first president the MLSTP Secretary General Manuel Pinto da Costa.

In 1990, São Tomé became one of the first African countries to undergo democratic reform, and changes to the constitution—including the legalization of opposition political parties—led to elections in 1991 that were non-violent, free, and transparent.

[citation needed] In July 2003, the army seized power for one week, complaining of corruption and that forthcoming oil revenues would not be divided fairly.

In September 2021, the candidate of the centre-right opposition Independent Democratic Action (ADI), Carlos Vila Nova, won the presidential election.

[45] In November of the same year, the government and military thwarted an attempted coup d'état,[46] after Patrice Trovoada was appointed Prime Minister of São Tomé and Príncipe by Carlos Vila Nova.

[47] The islands of São Tomé and Príncipe, situated in the equatorial Atlantic and Gulf of Guinea about 300 and 250 km (190 and 160 mi), respectively, off the northwest coast of Gabon, constitute Africa's second-smallest country.

Both islands formed about 30 million years ago during the Oligocene era, due to volcanic activity beneath deep water along the Cameroon Line.

The climate of São Tomé and Príncipe is essentially conditioned by its geographic location, subject to the seasonal translation of low equatorial pressures, the monsoon winds from the south, the warm Guinea Current and the relief.

The National Assembly, the supreme organ of the state and the highest legislative body, is made up of 55 members, who are elected for a four-year term and meet semiannually.

[61] In September 2022, Portugal and São Tomé and Príncipe signed a new cooperation agreement for defence, bolstering training and maritime security.

[70] Efforts have been made by the government in recent years to expand food production, and several projects have been undertaken, largely financed by foreign donors.

In 1987, the government implemented an International Monetary Fund structural adjustment program, and invited greater private participation in management of the parastatals, as well as in the agricultural, commercial, banking, and tourism sectors.

In late 2000, São Tomé qualified for significant debt reduction under the IMF–World Bank's Heavily Indebted Poor Countries initiative.

[75] São Tomé and Príncipe outperforms the sub-Saharan Africa average on the Human Development Index and has made great progress on most social indicators.

[76][75] In 2001, São Tomé and Nigeria reached an agreement on joint exploration for petroleum in waters claimed by the two countries of the Niger Delta geologic province.

[79][80] The main destinations for exports from São Tomé and Príncipe are Europe, where the Netherlands (19%), Portugal (14%), Poland (13%), France (7%) and Germany (6%) stand out.

In the 1970s, two significant population movements occurred — the exodus of most of the 4,000 Portuguese residents and the influx of several hundred São Tomé refugees from Angola.