In politics and history, a colony is a territory under the immediate political control of a state, distinct from the home territory of the sovereign. For colonies in antiquity, city-states would often found their own colonies. Some colonies were historically countries, while others were territories without definite statehood from their inception.
The metropolitan state is the state that rules the colony. In Ancient Greece, the city that founded a colony was known as the metropolis. "Mother country" is a reference to the metropolitan state from the point of view of citizens who live in its colony. There is a United Nations list of Non-Self-Governing Territories.
The term informal colony is used by some historians to refer to a country under the de facto control of another state, although this term is often contentious.
The word "colony" comes from the Latin word colōnia. This in turn derives from the word colōnus, which means colonist but also implies a farmer. Cologne is an example of a settlement preserving this etymology. Other, less obvious settlements that began as Roman colonia include cities from Belgrade to York. A tell-tale sign of a settlement once being a Roman Colony is a city centre with a grid pattern.  The terminology is taken from architectural analogy, where a column pillar is beneath the (often stylized) head capital, which is also a biological analog of the body as subservient beneath the controlling head (with 'capital' coming from the Latin word caput, meaning 'head'). So colonies are not independently self-controlled, but rather are controlled from a separate entity that serves the capital function.
Roman colonies first appeared when the Romans conquered neighbouring Italic peoples. These were small farming settlements that appeared when the Romans had subdued an enemy in war. A colony could take many forms, as a trade outpost or a military base in enemy territory. Its original definition as a settlement created by people migrating from a central region to an outlying one became the modern definition.
- Carthage formed as a Phoenician colony
- Cadiz formed as a Phoenician colony
- Cyrene was a colony of the Greeks of Thera
- Sicily was a Phoenician colony
- Durrës formed as a Greek colony
- Sardinia was a Phoenician colony
- Marseille formed as a Greek colony
- Malta was a Phoenician colony
- Cologne formed as a Roman colony, and its modern name refers to the Latin term "Colonia".
- Kandahar formed as a Greek colony during the Hellenistic era by Alexander the Great in 330 BC.
Modern historical examples
- Angola: a colony of Portugal since the 16th century. Independent since 1975.
- Argentina gained its independence from Spain in 1810 and formed the modern constitution in 1853.
- Australia was formed as an independent country in 1901 from a federation of six distinct British colonies which were founded between 1788 and 1829.
- Barbados: was a colony of Great Britain important in the Atlantic slave trade. It gained its independence in 1966.
- Brazil: a colony of Portugal since the 16th century. Independent since 1822.
- Canada: colonized first by France as New France (1534-1763), then under British rule (1763–1867), before achieving Dominion status.
- Congo, Democratic Republic of the: a colony of Belgium from 1908 to 1960.
- French Indochina was formed in October 1887 from Annam, Tonkin, Cochinchina (which together form modern Vietnam) and the Kingdom of Cambodia; Laos was added after the Franco-Siamese War in 1893. The federation lasted until 1954. In the four protectorates, the French formally left the local rulers in power, who were the Emperors of Vietnam, Kings of Cambodia, and Kings of Luang Prabang, but in fact gathered all powers in their hands, the local rulers acting only as figureheads.
- Ghana: Contact between Europe and Ghana (known as The Gold Coast) began in the 15th century with the arrival of the Portuguese. This soon led to the establishment of several colonies by European powers: Portuguese Gold Coast (1482–1642), Dutch Gold Coast (1598-1872), Swedish Gold Coast (1650-1663), Danish Gold Coast (1658-1850), Brandenburger and Prussian Gold Coast (1685-1721) and British Gold Coast (1821-1957). In 1957, Ghana was the first African colony south of the Sahara to become independent.
- Greenland was a colony of Denmark-Norway from 1721 and was a colony of Denmark from 1814 to 1953. In 1953 Greenland was made an equal part of the Danish Kingdom. Home rule was granted in 1979 and extended to self-rule in 2009. See also Danish colonization of the Americas.
- Guinea-Bissau: a colony of Portugal since the 15th century. Independent since 1974.
- Hong Kong was a British colony from 1841 to 1997. Is now a Special Administrative Region of China.
- India Major parts of India were under the direct control of the government of the United Kingdom between 1858 and 1947. After 1947, British India was split into India and Pakistan. See also Crown colony. However Britain was not the only colonial power in India. From the 15th century until 1961, parts of modern India belonged to Portugal and were collectively known as Portuguese India. Other parts (the town of Tharangambadi, Serampore and the Nicobar Islands) belonged to Denmark from 1620 to 1869 and were known as Danish India.
- Indonesia was a Dutch colony for 350 years, from 1600 to 1949. During World War II, it was occupied by the Japanese military from 1942 to 1945.
- Jamaica was part of the Spanish West Indies in the sixteenth and seventeenth centuries. It became a British colony in 1655, then gained its independence in 1962.
- Liberia was the only African nation on the African continent that was a colony for the United States of America and a protectorate from 1821 until the Liberian Declaration of Independence from the American Colonization Society on July 26, 1847. Liberia is Africa's oldest republic nation and the second oldest black republic in the world after Haiti. Liberia was founded, colonized, established and controlled by the American Colonization Society, a private organization who sent freed slaves from America and the Caribbean to Liberia as colonists to settle. Due to its backing and support from the United States, Liberia remained legally independent during the colonial era.
- South Africa consisted of territories and colonies by various different African and European powers, including the Dutch, the British, and the Nguni. The territory consisting the modern nation was ruled directly by the British from 1806-1910, at which point power gradually devolved from London until all remaining legal ties were formally severed in 1961.
- Macau was a Portuguese colony from 1557 to 1999. In 1999, two years after Hong Kong, it became a Special Administrative Region of China.
- Malta was a British protectorate and later a colony from the French Revolutionary Wars in 1800 to independence in 1964.
- Mozambique: a colony of Portugal since the 15th century. Independent since 1975.
- Philippines, previously a colony of Spain from 1521 to 1898 as part of the Spanish East Indies, was a colony of the United States from 1898 to 1946. Achieved self-governing Commonwealth status in 1935. During World War II between 1942 and 1945, it was occupied by the Japanese forces. Its independence was recognized in 1946.
- Somalia, was a colony of Italy and Britain from the late 1800s to 1960. On July 6, 1960, the Trust Territory of Somaliland (former Italian Somaliland) united as planned with the former British Somaliland to form the Somali Republic (Somalia).
- Sri Lanka a British colony from 1815 to 1948. Known as Ceylon. Was a British Dominion until 1972.
- Taiwan had a Dutch colony (1624–1662) centered on present-day Tainan; shortly afterwards, a Spanish colony (1626–1642) was established concurrently in northern Taiwan, not far from present-day Taipei.  Chinese colonial rule was established when Han Chinese forces loyal to the Ming Dynasty defeated the Dutch in 1662.  The Ming loyalists later surrendered Taiwan to the Qing Dynasty, which annexed Taiwan into Chinese territory, making it part of Fujian province, and later making it a province in its own right. Qing dynasty rule ended after the First Sino-Japanese War when the Qing ceded Taiwan to Japan, placing Taiwan under Japanese control (1895-1945). After the defeat of Japan in World War II, Taiwan was given to the Republic of China, becoming its base after its defeat in the Chinese civil war.
- The United States was formed from a union of thirteen distinct English/British colonies in British America. The Colony of Virginia was the first of the thirteen colonies. All thirteen declared independence in July 1776 and expelled the British governors.
The Special Committee on Decolonization maintains the United Nations list of Non-Self-Governing Territories, which identifies areas the United Nations (though not without controversy) believes are colonies. Given that dependent territories have varying degrees of autonomy and political power in the affairs of the controlling state, there is disagreement over the classification of "colony".