Black's Law Dictionary (2nd edition)dictionaries

Heptarchy

A government exercised by seven persons, or a natlon divided into seven governments. In the year 560, seven dlfferent monarchies had been formed in England by the German tribes, namely, that of Kent by the Jutes; those of Sussex, wes-sex, and Essex by the Saxons; and those of East Anglia, Bernlcia, and Deira by the An-gles. To these were added, about the year 586, an eighth, called the “Kingdom of Mer-cla,” also founded hy the Angles, nnd com-prehendlng nearly the whole of the heart of the kingdom. These states formed what has been designated the “Anglo-Saxon octarchy,” • or more commonly, though not so correctly, the “Anglo-Saxon Heptarchy," from the cus-tom of speaking of Delra and Bernicia under the single appellation of the “Kingdom of Northumberland." wharton

Source: Black's Law Dictionary 2nd Ed (1910)