Complex sentence: The formal concept of civil liberties dates back to the English legal charter Magna Carta, sealed in 1215, which in turn was based on pre-existing documents namely the Charter of Liberties, a landmark document in English legal history and constitutional history.
Split into simpler sentences: The formal concept of civil liberties dates back to the English legal charter Magna Carta, which in turn was based on pre-existing documents namely the Charter of Liberties. Sealed in 1215, Magna Carta is a landmark document in English legal history and constitutional history.