Heptarchy

A government exercised by seven persons or a nation divided into seven governments. In the year 560, seven different monarchies had been formed in England by the German tribes, namely, that of Kent by the Jutes; those of Sussex, Wessex, and Essex by the Saxons; and those of East Anglia, Bernicia, and Deira by the Angles. To these were added, about the year 586, an eighth, called the "Kingdom of Mercia," also founded by the Angles, and comprehending 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 custom of speaking of Deira and Bernicia under the single appellation of the "Kingdom of Northumberland."

Wharton.