John Marshall is considered by many to be the master builder of the Supreme Court. The nation's fourth Chief Justice of the Supreme Court and longest serving Chief Justice, Marshall is credited with bolstering the function and role of the Supreme Court in the many decisions and writings he offered on the subject. Of these, the most important would have to be Marshall's decision in the case of Marbury v. Madison. The case centered on which branch has the power to declare acts of Congress and actions of the Executive as unconstitutional. Marshall wrote that only the Supreme Court can determine constitutionality, providing it with the ultimate check on the other two branches. Marshall believed that federal courts, and in particular the Supreme Court, held more power than local or state courts. In this light, Marshall was seen as one of the most vocal advocates for the powers of the Judicial Branch, certainly one of the passionate of the branch at the time. Marshall's greatest relevancy would be his zeal for the court and the articulation of its power to declare laws and actions unconstitutional, something that has defined the court since Marshall's time.