Tellurocracy in the context of "Imamate of Oman"

An empire is a realm controlled by an emperor or an empress and divided between a dominant center and subordinate peripheries. The center of the empire (sometimes referred to as the metropole) has political control over the peripheries. Within an empire, different populations may have different sets of rights and may be governed differently. The word "empire" derives from the Roman concept of imperium. Narrowly defined, an empire is a sovereign state whose head of state uses the title of "emperor" or "empress"; but not all states with aggregate territory under the rule of supreme authorities are called "empires" or are ruled by an emperor; nor have all self-described empires been accepted as such by contemporaries and historians (the Central African Empire of 1976 to 1979, and some Anglo-Saxon kingdoms in early England being examples).

There have been "ancient and modern, centralized and decentralized, ultra-brutal and relatively benign" empires. An important distinction has been between land empires made up solely of contiguous territories, such as the Achaemenid Empire, Roman Empire, the Mongol Empire, or the Russian Empire; and those - based on sea-power - which include territories that are remote from the 'home' country of the empire, such as the Dutch colonial empire, the Empire of Japan, the Chola Empire or the British Empire.

A thalassocracy or thalattocracy, sometimes also maritime empire, is a state with primarily maritime realms, an empire at sea, or a seaborne empire. Traditional thalassocracies seldom dominate interiors, even in their home territories. Examples of this were the Phoenician states of Tyre, Sidon and Carthage; the Italian maritime republics of Venice and Genoa of the Mediterranean; the Omani Empire of Arabia; and the empires of Srivijaya and Majapahit in Maritime Southeast Asia. Thalassocracies can thus be distinguished from traditional empires, where a state's territories, though possibly linked principally or solely by the sea lanes, generally extend into mainland interiors in a tellurocracy ("land-based hegemony").

The term thalassocracy can also simply refer to naval supremacy, in either military or commercial senses. The ancient Greeks first used the word thalassocracy to describe the government of the Minoan civilization, whose power depended on its navy. Herodotus distinguished sea-power from land-power and spoke of the need to counter the Phoenician thalassocracy by developing a Greek "empire of the sea".