Question: William Sharp McKechnie, was a Scottish scholar, historian, lecturer in Constitutional Law and History, and author of which charter commonly known as, and agreed to by King John of England at Runnymede, near Windsor, on 15 June 1215?
Context: Michael William McConnell (born May 18, 1955 in Louisville, Kentucky) is a constitutional law scholar who served as a United States Circuit Judge of the United States Court of Appeals for the Tenth Circuit from 2002 until 2009.  Since 2009, McConnell has served as Director of the Stanford Constitutional Law Center at Stanford Law School.  He is also a senior fellow at Stanford University's Hoover Institution, and of Counsel to the Litigation Practice Group at Kirkland & Ellis LLP. Michael J. Klarman is an American legal historian, and constitutional law scholar, the Kirkland & Ellis Professor at Harvard Law School.  Formerly, he was James Monroe Distinguished Professor of Law, Professor of History, and Elizabeth D. and Richard A. Merrill Research Professor at the University of Virginia School of Law.  Klarman specializes in the constitutional history of race.  He contends that the Supreme Court of the United States has historically been hostile to the rights of minorities and has not consistently enforced constitutional protections for them.  Klarman argues that civil rights protections arise out of social mores from which the court takes its cue. Ephraim S. London (June 17, 1911 – June 12, 1990) was an American attorney and law professor specializing in constitutional law who established a reputation as a defender of free speech and civil liberties.  He taught constitutional law at the New York University School of Law, his alma mater.  He wrote "The World of Law", a textbook that was widely used in law schools.  He was also the author of "The Law as Literature". Ronald D. Rotunda (born 1945) is a U.S. legal scholar and professor of law at Chapman University School of Law.  Rotunda's first area of primary expertise is United States Constitutional law, and is the author of an influential 6-volume legal treatise on Constitutional Law.  His other area of primary expertise is Legal Ethics, often called Professional Responsibility.  He has also published an influential treatise on Legal Ethics, co-published by West-Thomson Reuters, ABA.  He was also a senior fellow, in 2000, at the Cato Institute in Washington, D.C. Mahendra Pal Singh (born 15 July 1940), popularly known as M.P. Singh, is a constitutional law scholar of India.  He is best known amongst students of Constitution of India for being the revising author of "V.N. Shukla's Constitution of India" a standard textbook for lawyers on Constitution of India.  Internationally however, he is more famous amongst scholars of comparative constitutional law and comparative administrative law for his work, "German Administrative Law in Common Law Perspective". William Sharp McKechnie (2 September 1863 – 2 July 1930) was a Scottish scholar, historian, lecturer in Constitutional Law and History, and author of "Magna Carta: A Commentary on the Great Charter of King John with an Historical Introduction".  He later held the Chair of Conveyancing at the University of Glasgow from 1916 until 1927.  Upon his retirement, he was awarded an honorary LL.D. Kenji Yoshino (born c. 1969) is a legal scholar and the Chief Justice Earl Warren Professor of Constitutional Law at New York University School of Law.  Formerly, he was the Guido Calabresi Professor of Law at Yale Law School.  His work involves Constitutional law, anti-discrimination law, civil and human rights, as well as law and literature, and Japanese law and society.  He is actively involved with several social and legal issues and is also an author. Sir Robert de Ros, or de Roos of Helmsley, (ca. 1170/1172 – 1227), was the grandfather and ancestor of the Barons Ros of Helmsley that was created by writ in 1264.  In 1215, Ros joined the confederation of the barons at Stamford.  He was one of the twenty-five barons to guarantee the observance of Magna Carta, sealed by King John on 15 Jun 1215. Francis Joseph "Frank" Scaturro (born July 26, 1972) is an American lawyer, historian, public advocate, and politician.  As a college student, he spearheaded the restoration of Grant's Tomb in New York City’s Riverside Park, and wrote a reassessment of Ulysses S. Grant’s presidency.  Scaturro is a constitutional law expert and served as Counsel for the Constitution on the U.S. Senate Judiciary Committee from 2005 to 2009, and helped coordinate the nomination process to elevate John Roberts and Samuel Alito to the United States Supreme Court.  Scaturro published other books and articles about history, constitutional law, and public policy.  He ran for Congress in 2010, 2012 and 2014 in New York's 4th congressional district on Long Island, but was defeated each time. Magna Carta Libertatum (Medieval Latin for "the Great Charter of the Liberties"), commonly called Magna Carta (also "Magna Charta"; "(the) Great Charter"), is a charter agreed to by King John of England at Runnymede, near Windsor, on 15 June 1215.  First drafted by the Archbishop of Canterbury to make peace between the unpopular King and a group of rebel barons, it promised the protection of church rights, protection for the barons from illegal imprisonment, access to swift justice, and limitations on feudal payments to the Crown, to be implemented through a council of 25 barons.  Neither side stood behind their commitments, and the charter was annulled by Pope Innocent III, leading to the First Barons' War.  After John's death, the regency government of his young son, Henry III, reissued the document in 1216, stripped of some of its more radical content, in an unsuccessful bid to build political support for their cause.  At the end of the war in 1217, it formed part of the peace treaty agreed at Lambeth, where the document acquired the name Magna Carta, to distinguish it from the smaller Charter of the Forest which was issued at the same time.  Short of funds, Henry reissued the charter again in 1225 in exchange for a grant of new taxes; his son, Edward I, repeated the exercise in 1297, this time confirming it as part of England's statute law.
Answer: Magna Charta