Sod the Magna Carta - which was mostly about Baron Power - which they got and have never let go of.
If we're going Medieval, we can have John Ball, one of the leaders of the Peasants' Revolt, preaching this sort of thing in and around 1380. (Peasants' Revolt 1381)
'My good people, things cannot go well in England, nor ever shall, till everything be made common, and there are neither villeins nor gentlemen, but we shall all be united together, and the lords shall be no greater masters than ourselves. What have we deserved that we should be kept thus enslaved? We are all descended from one father and mother, Adam and Eve. What reasons can they give to show that they are greater lords than we, save by making us toil and labour, so that they can spend? They are clothed in velvet and soft leather furred with ermine, while we wear coarse cloth; they have their wines, spices and good bread, while we have the drawings of the chaff, and drink water. They have handsome houses and manors, and we the pain and travail, the rain and wind, in the fields. And it is from our labour that they get the means to maintain their estates.'