The 7 Kingdom based on the 7 Anglo-Saxon kingdoms?

Obviously. Looking for a match is pointless but the idea is the same.
The First Men are parallel to the original Celtic civilisation. The Andals arriving later echo that of the Anglo-Saxons, although they take control of already existing kingdoms while those of the historical heptarchy betray their Anglo-Saxon origin by their very names.
The Targaryen conquest is then equivalent to the Franco-Norman invasion of 1066.

Robert's Rebellion and the War of the Five Kings do not have an exact historical match either but are clearly inspired from the Wars of the Roses. Ned Stark even gets part of the Richard III treatment: named Protector of the Realm, he is made to confess he plotted to kill Joffrey and make himself king in spite of the rules of succession, which is also the version depicted in the Braavos play of Season 6.