University of Minnesota
Most of the early English jurists who wrote about English law did not write specifically about the Magna Carta. Although the Great Charter was reconfirmed numerous times during the two centuries after Henry III issued its final version in 1225, it was not the direct subject of much legal commentary. During those centuries, actions by parliament made it statutory law, the first of the ancient statutes of England. Jurists who wrote significant accounts of English law dealt primarily about cases with which they were familiar, thus building the foundations of English common law. Nevertheless, any reading of the earlier jurists indicates that the principles of the Charter informed the fundamental view of English law articulated in their treatises. As J. C. Holt has written about these early jurists, "It is true that neither Fortescue nor Littleton gave much space to Magna Carta, but nor had Bracton. Certainly Fortescue made no mention of it in his paean of praise for English law; even so, it underlay some of the main points of his argument. It would be impossible to find chapter and verse for what he had to say about lex terrae as it applied to arrest, trial, or threat to possessions without calling in the end on the Charter." 
Conscious reference to the Charter, however, increased during the Tudor and especially during the Stuart eras, when the monarchs sought to expand their prerogatives in ways that were seen to be in conflict with established liberties. The most complete of the commentaries at this time was that of Sir Edward Coke (1552-1634). This was also the period during which the numbers of lawyers in England increased substantially, creating a large demand for books dealing with the law. Between 1530 and 1550, the four Inns of Court (where legal training took place) averaged a total of eight to ninety admissions per year; by 1588-1584, the number had risen to two hundred, and between 1615 and 1619, it reached over three hundred, after which the number again began to decline
What follows is a brief description of the major commentaries on English law from the thirteenth to the eighteenth century.
Henry de Bracton (c. 1210-1268)
Bracton's chief work was De Legibus et Consuetudinibus Angliae (The Laws and Customs of England), some of which was probably the work of William Raleigh, who was Bracton's mentor, then added to and updated by Bracton, who is thus credited with the work. Bracton's other contribution was the Note Books, which provide commentary on roughly two thousand cases from the plea rolls that came into his possession. Bracton was not seeking to develop "case law" or authority derived from the cases about which he wrote; there was no sense of stare decisisin his commentary, but in some of the cases he selected, he occasionally offered praise or criticism. Plucknett suggests that Bracton's method, offering commentary on cases, created a demand for more case-based commentary and thus may have given rise to the later preparation of the Year Books.
Bracton is said to have been somewhat influenced by Roman Law as he had studied the work of a famous Italian lawyer, Azo of Bologna as well as Justinian's Corpus Iuris Civilisand canon law. He borrowed from them large maxims as might be derived from universal or natural law, but "the main matter of his treatise is genuine English law laboriously collected out of the plea rolls of the King's court."
Bracton apparently did not take sides in the Second Baron's War (1264-67), although, consistent with the position of the barons who had demanded the Magna Carta from King John in 1215, he was clearly opposed to unrestrained royal power. Thus the recognition of the force of the Magna Carta lay at the basis of his view of the law and royal authority. He wrote, "The king has a superior, namely God. Also the law, by which he was made king. Also his curia, namely the earls and barons, because if he is without bridle, that is without law, they ought to put a bridle on him." In addition, "The king must not be under man, but under God and the law, because the law makes the king...for there is no rexwhere will rules rather than lex."
John Fortescue (1395-1480)
Fortescue is best known for his book,De Laudibus Legum Angliae ( In Praise of the Laws of England), which is a didactic account of law and governance in the form of a dialogue between a prince and his teacher. In this case, the prince is probably Prince Edward, son of Henry VI of the House of Lancaster, during his exile in the War of Roses. Fortescue served the House of Lancaster as Chief Justice of the King's Bench from 1442 to 1461 and was also elected to the House of Commons eight times, experiences which shaped the central maxim of his writing: "A King of England cannot at his pleasure, make any alterations of the laws of the land, for the nature of government is not only regal, but political."
Fortescue's work is as much an articulation of political philosophy as it is a commentary on law. Following Aristotle and Aquinas, he sees laws having their origin in nature, analogous to the elements and form that determine material nature: "...now in the laws these are not, properly speaking matter and form, these being what to the composition of natural things; but something analogous to it however, viz. certain elements out of which they arise, as Customs, Statutes, or Acts of Parliament and the Law of Nature: whereof the laws of particular kingdoms consist, as natural things do of matter and form...." 
Government originated, for Fortescue, in a contract between the community and the ruler, wherein the ruler is charged with protecting those whom he governs. In this, he anticipates the later social contract theories of Hobbes and Locke. He writes: "...it is absolutely necessary, where a company of men combine to form themselves into a body politic, that some one should preside as the governing principal, who goes usually under the name of King.....For he is appointed to protect his subjects in their lives, properties and laws; for this very end and purpose he has the delegation of power from the people; and he has no just claim to any other power than this." 
In this, as in his declaration that the king cannot levy taxes without the consent of his subjects, in his definition of justice derived from sworn juries, "twelve men good and true," in contrast to the judicial use of torture in contemporary France, whose despotism he specifically denounced, Fortescue reflected the principles of the Magna Carta.
Sir Edward Coke (1552-1634)
Sir Edward Coke was perhaps the most famous jurist in England during the reigns of Elizabeth I, James I, and Charles I. He held numerous prominent positions, among them Speaker of the House of Commons, Solicitor General, Attorney General, Chief Justice of the Common Pleas, and Chief Justice of the King's Bench. As Attorney General, he prosecuted Sir Walter Raleigh in 1603 and the conspirators in the Gunpowder Plot in 1605. By ruling against the actions of James I in 1616, he lost the King's favor and was subsequently dismissed from office. His judicial career at an end, he re-entered the House of Commons where he became a frequent critic of James I and Charles I. In response to Charles' imposition of taxes without parliamentary approval and his imposition of martial law, Coke drafted The Petition of Right, which passed both houses of parliament and was ultimately signed by Charles. The Petition of Right proclaimed various "rights and liberties" of free Englishmen, including freedom from taxation without approval from parliament, the right of habeas corpus , a prohibition against the billeting of soldiers in the homes of civilians against their will, and a prohibition against imposing martial law on civilians. The Petition of Right, along with the Magna Carta, and the Bill of Rights of 1689 are seen as the major pillars of English civil liberties and constitutional law. It also profoundly influenced the drafters of the U.S. Constitution.
As the leading expert on English legal history, Coke published the Law Reports, a summary and commentary on the legal cases with which he was familiar or in which he had participated. As a compendium of legal decisions it became a textbook for English lawyers. It had a profound impact on the evolution of English law. His four-volume study, Institutes of the Lawes of England, considered his masterpiece, also had a significant impact on legal thought in England and the United States. The first volume, a commentary on Sir Thomas Littleton's Treatise on Tenuresdealt with the history of law related to land-ownership. The second volume dealt with "ancient statutes," provided a chapter-by-chapter exposition of the Magna Carta and legal decisions related to it. The third volume dealt with treason., and the fourth with the jurisdiction of the courts.
Coke's commentary on the Magna Carta was the first commentary on law to analyze the Magna Carta chapter by chapter and to add the commentary on law cases that pertained to each chapter. His resurrection of the Magna Carta provided a reference to the ancient liberties guaranteed to Englishmen and thus became especially important in shaping the legal thought for resistance to the rule of Oliver Cromwell and preparing the legal foundation for the Glorious Revolution.