Magna Carta the King in the charters. In addition, medieval cases referred to the clauses in Magna Carta which dealt with specific issues such as wardship and dower, debt collection, and keeping rivers free for navigation. Even in the 13th century, some clauses of Magna Carta rarely appeared in legal cases, either because the issues concerned were no longer relevant, or because Magna Carta had been superseded by more relevant legislation. By 1350 half the clauses of Magna Carta were no longer actively used. During the reign of King Edward III six measures, later known as the "Six Statutes", were passed between
Magna Carta the relevant roles. Although these clauses did not have any special significance in the original charter, this part of Magna Carta became singled out as particularly important in later centuries. In the United States, for example, the Supreme Court of California interpreted clause 45 in 1974 as establishing a requirement in common law that a defendant faced with the potential of incarceration be entitled to a trial overseen by a legally trained judge. Royal forests were economically important in medieval England and were both protected and exploited by the Crown, supplying the King with hunting grounds, raw materials, and money.