A few modern colonies have been convict settlements, or founded primarily as an outlet for population; but most have been founded originally with a view to trade. Venice in the Middle Ages held a number of dependencies in Albania, Greece, and elsewhere, held and governed solely in the interests of her trade. During the 15th century the Portuguese pushed their way along the West African coast, occupied Madeira, the Azores, and points on the mainland, and were followed by the Spanish. In 1492 Columbus found his way to the West Indies; in 1497 the Portuguese doubled the Cape of Good Hope, and founded several trading ports (on the Venetian plan) in India. One or other of these nations speedily conquered various parts of South and Central America, solely, it would seem, with a view to the stores of gold and silver that existed there. Grants of land were, however, made to Spanish and Portuguese subjects, who settled and worked their estates much as they would have done at home. The English colonies were founded partly also with a view to obtain gold and silver, but were usually managed by commercial companies; Newfoundland was founded in 1607, Virginia in the same year. But the decay of the old land system in England and the religious difficulties stimulated emigration, as in the case of the Pilgrim Fathers, and many of Cromwell's Irish and Scottish prisoners were sent by him to the West Indies and the Carolinas. So also after Monmouth's rebellion; and convicts were long sent to Virginia. The French colony in Canada was founded in 1603. The Dutch gradually supplanted Portugal in the East 1602-1609, and founded Batavia (q.v.) in 1618. All European natives regarded their colonies at first as sources of a supply of gold and silver; when it was found that many of them did not contain it, their trade was put under oppressive restrictions to give the mother country the monopoly of their commerce. They were regarded as providing markets for its manufactures, and as furnishing it with valuable products which it could sell for specie. This "colonial system" was most thoroughly applied by Spain and Portugal, with the effect of checking their own development, by withdrawing their capital, as well as hampering the progress of their colonies. In England it originated under Cromwell, but was far less thoroughly applied than abroad. Still, the usual relation of official England to the colonies in the last century may be illustrated by the story of the English statesman who, being asked to appoint chaplains for the good of the souls of the colonists, cursed their souls and bid them grow tobacco.
The rising in Canada (q.v.) in 1837 made it necessary to concede responsible government to it. Victoria was the first Australian colony to receive a like privilege (in 1857). At present there are three classes of English colony: - Crown colonies, which are governed from the Colonial Office, colonies with representative institutions but not responsible government, in which the Home Government has a veto on legislation, and colonies with responsible government, like Canada and New South Wales, between which and the mother country the Governor-General is practically the only political link. (For the various English colonies see separate headings.) Of foreign nations, only France, Spain, Portugal, and Holland now possess important colonies. Denmark has Iceland, a few settlements in Greenland, and some small West Indian islands; Spain has Cuba, Porto Rico, the Philippine, Caroline, and other islands; Portugal holds Goa, Macao, the Cape Verde Islands, and settlements on the coast of E. and W. Africa; Holland has Java, Sumatra, and other East Indian islands, Surinam, and some islands off the coast of Venezuela; France has part of Guiana, and also possessions in India, Cochin China, W. Africa, and Oceania, besides protectorates in Madagascar, Tunis, Annam.etc. (Algeria does not rank as a colony). Italy possesses one small and useless colony in Abyssinia. The area and population of these colonies is approximately as under (excluding protectorates and spheres of influence): -
| Area - sq. miles. | Population | |
| Colonies of France | 1,574,000 | 40,000,000 |
| Colonies of Holland | 766,000 | 30,000,000 |
| Colonies of Spain | 407,000 | 12,000,000 |
| Colonies of Portugal | 866,000 | 5,800,000 |
| Colonies of Denmark | 87,000 | 116,000 |
| British Colonies (excluding India) | 7,200,000 | 20,000,000 |
British India, with its 210 millions of population and more than a million square miles of area, has more right to be considered a colony than most foreign colonies so-called.
The French colonies are represented in the legislature; the colonies of other countries are governed much like the British Crown colonies.
The doctrine of the last century, that colonies should serve as markets for home produce, still governs the colonial policy of most foreign countries, owing to the prevalence of Protectionism.
Colonisation on a great scale has seldom been carried out on any scientific system. Prof. Seeley has remarked that the English people seem almost to have picked up their colonial empire in a fit of absence of mind. Mr. E. G. Wakefield some sixty years ago suggested that care should be taken to send out artisans as well as agriculturists to Australia, that the various classes of producers might exchange their wares and so stimulate production. His advice was followed in "assisted emigration," which has, however, now been generally discontinued.