America, Africa and Oceania were all colonized, China and Japan in Asia were semi-colonies, and Korea was occupied by Japan after the Sino-Japanese War, which can be understood as a colony of Japan, while South Asia and Southeast Asia were colonies of western powers. But these western suzerainties were conquered by the more powerful Rome in ancient times, including Spain, Portugal, France, the Netherlands, Belgium and Germany, and some of them won. Northern Europe is vast and sparsely populated, with a cold climate and has never been colonized. Once the whole Mediterranean was an inner lake of Rome, so the Mediterranean coast could be classified as a colony. Alexander the Great of Macedonia defeated Greece and conquered Persia, and the whole of West Asia can also be classified as a colony. Siberia and Russia were once conquered by Mongolia and established the rule of the Mongolian khanate, which was also considered a colony. Sicily and southern Italy were colonies of Greek city-states during the Roman monarchy and Republic, and the Roman Empire was also captured by Germans and Goths. The arrival of the Middle Ages in Europe, until the Renaissance, was a struggle between feudal countries and a dispute between religious factions, which was neither colonized nor colonized. There are two questions: First, whether the semi-colonies were colonized; if so, China, Japan, the Korean Peninsula and Southeast Asia were all colonized. After Columbus discovered the new continent during the great voyage, the whole America was a colony. Second, is being conquered a colony? If so, the modern countries and ancient countries in the same land are integrated, Spain and Portugal on the Iberian Peninsula and some central and western European countries including Britain were conquered and colonized by Rome, and the Roman conquest even crossed the Danube and Rhine.

To sum up, the Nordic countries and parts of Central Europe have not been colonized.