The "Assemblies of Estates" and the "Estates-General" of the Middle Ages (and the modern period) were based on this principle. Some historians stress the differences between the medieval "Assemblies of Estates" and the representa tive assemblies that became the locus of power in the wake of the three great revolutions. The differences are indeed substantial. However, they should not obscure the elements of continuity. The fact is that the English Parliament after the revolutions of 1641 and 1688 was also the descendant of the Parliament of the "ancient constitution" - and was seen as such.