imperium, in political geography, a large extent of land, under the jurisdiction or government of an emperor. See Emperor.

The most ancient empire we read of, is that of the Assyrians, which was subverted through the effeminacy of Sardanapalus; the Persian empire was destroyed through the bad conduct of Darius Codomannus; the Grecian empire, by its being dismembered among the captains of Alexander the Great; and the Roman empire, through the ill management of the last emperors of Rome.

Antiquaries distinguish between the medals of the upper, and lower or bar, empire.—The curious only value those of the upper empire, which commences with Caesar, or Augustus, and ends in the year of Christ 260.

The lower empire comprehends near 1200 years, reckoning as low as the destruction of Constantinople in 1453. They usually distinguish two ages, or periods, of the lower empire: the first beginning where the upper ends, viz. with Aurelian, and ending with Anastasius, including 200 years; the second beginning with Anastasius, and ending with the Palaeologi, which includes 1000 years.

or *The empire*, used absolutely, and without any addition, signifies the empire of Germany; called also, in juridical acts and laws, The holy Roman empire. Authors are at a loss under what form of government to range the empire: some will have it a monarchical state, by reason all the members thereof are forced to ask the investiture of their states of the emperor, and to take an oath of fidelity to him. Others will have it an aristocratic state, by reason the emperor cannot determine anything without the concurrence of the princes: and, lastly, others will have the empire to be a monarcho-aristocratic state.