This paper considers how the English episcopate's complaints (gravamina) of 1253 demonstrate one view of how the king's authority could be curbed through Magna Carta and the Charter of the Forest. The gravamina were drafted by Robert Grosseteste, bishop of Lincoln 1235-1253, and declare that the king is ignoring universal, natural law, and man-made common law. They reveal Grosseteste's own view of the relationship between justice and natural law and how this should influence written law codes to ensure the salvation of mankind. Grosseteste interpreted the charters of liberties through natural law, as intended to bring common law and natural law into line with each other to make salvation possible through the exercise of justice. Magna Carta was now not an immediate solution to a local problem, but part of a universal, eternal concern. As the document was issued in the names of all the episcopate they also consented to this view. 1 Those charters were Magna Carta and its sibling, the Charter of the Forest. 2 They were already, by the mid-thirteenth century, beginning to be seen as having enduring power to curb royal excess, and were to underpin the development of English ideas of justice and law, becoming iconic symbols of national identity. This article explores how and why Grosseteste, a man who forcefully rejected any idea that Church and State should come under the same form of government, conceived of and engaged with these foundational charters of the English state. It examines the ways in which these charters, although local solutions to local problems, reflect the broader international Christian intellectual culture, as understood and articulated by Robert Grosseteste, and suggests that Grosseteste's gravamina of 1253,