The metropole of the Roman Empire was Italy. As the homeland of the Romans, it also maintained a special status which made it "not a province, but the Domina of the provinces". Italy was federated by the Romans in the third century BC. Unlike the overseas and ultramontane territories conquered by the Romans, Italy, due to the presence of Rome in the peninsula, was not reduced to province status. Originally, Rome divided the Italics into three groups: Roman citizens, Latini, and socii. After 88 BC, all Italics were made Roman citizens. Italy continued to have this privileged status until 212 AD, when citizenship was extended to all the inhabitants of the Empire. From Caesar Augustus to Septimius Severus, all Roman Emperors were Italics. The term Ius Italicum identified the Roman Italian privileges, especially when it came to taxation, which could be extended to certain communities outside of Italy under certain conditions.
The Metropole is the British metropolitan centre of the British Empire; i.e., the United Kingdom itself. It is sometimes used even more specifically to refer toLondon as the metropole of the British Empire, insofar as its politicians and businessmen determined the economic, diplomatic, and military character of the rest of the Empire. By contrast, the was the rest of the Empire, outside the United Kingdom itself. The historiography of British metropole-periphery relations has traditionally been defined in terms of their distinct separation, with a pronouncedly one-way, near-dictatorial channel of command, communication, and control proceeding outward from the centre; the metropole informed the periphery, but the periphery did not directly inform the metropole. Hence, the British Empire was constituted by the formal control of territories, by direct rule of foreign lands, instigated by the metropole. More recent work, starting with that of John Gallagher and Ronald Robinson in the 1950s, has questioned the traditional definition, positing instead that the two were mutually constitutive and maintaining that, despite the apparent temporal inconsistencies inherent in their separate existences, each formed simultaneously in relation to the other. Gallagher and Robinson were socialists, observing the rise of the economic power of the United States in the developing world at a time when the African colonies of the British Empire were being granted independence; both scholars held that British and American "empires" were ultimately developed along similar lines. In the context of Gallagher, Robinson, and Adlai Stevenson's theories of "free trade imperialism", the use of soft power, primarily through the employment of British capital, allowed the United Kingdom to extract concessions, namely free trade for British manufactured goods, just as readily as if they had engaged in a costly military occupation of the territories. In this interpretation, the economic informal Empire of the periphery constituted a formal "Empire" just as surely as the metropole did.
In the scope of the Portuguese Empire, the Metrópole was the European part of Portugal, which included Continental Portugal and the adjacent islands. It corresponded to the present territory of Portugal. Until the mid 19th century, the Portuguese European territory was referred to as "Portugal" or as the "Kingdom". However, these terms became inappropriate when the Portuguese overseas territories gained the status of overseas provinces in 1832, and came to be considered an integral part of the Kingdom of Portugal alongside its European provinces. The use of the term "Metrópole" emerged then as the official designation of the European part of Portugal. From then on, and until the independence of most of the remaining Portuguese overseas territories in 1975, Portugal included the Metrópole and the Overseas.
