  A stage of human history rather later than that of savages was delineated within An Abridgement of English History, which Burke wrote after 1757, but did not finish. So far as it goes, this provided a continuous account that ran from the Roman landings to Magna Carta. Christianity figured again in this narrative as a source of civilization, but the significance of the tale was more complex. This time the story was primarily political, and showed how one of the values most prized by Burke's contemporaries, civil liberty, came to belong to England. The Norman Conquest of England established a powerful executive government and brought with it a uniform system of law; if these two were necessary conditions for the matching grace of civil liberty for all, however, they were not sufficient: the required addition came from an aristocracy, which had been taught the value of liberty by the Archbishop of Canterbury, and which had come to understand that its own power was insufficient to extract the requisite concessions from the crown unless popular support could be won. Burke's sense of the double-edged character of civilization thus developed into a sense that the political regime required by an advanced society—the combination of strong institutions with civil liberty—came from sources that were contrary to each other, and not always beneficial in isolation (aristocracy as a form of government was an ‘austere and insolent domination’ (TCD, W &amp; S, 1981–2015, ii. 268)): and as both a strong executive and civil liberty were needed, by the same token the forces making for each needed to be counterbalanced from the other side on a continuing basis. This balance of forces characterised a situation in which ‘liberty’ had an identifiable content, namely the specific civil liberties secured through political struggle and written into Magna Carta.