Law of the land

The phrase law of the land (Latin lex terrae) is a legal term. It means all of the laws in force within a country or region. The term was first used in the Magna Carta. It was used to mean the laws of the kingdom. This was distinct from Roman law or civil law. In the United States, the Constitution declares it is the "supreme law of the land." It is the same as due process of law as justified by the Constitution.
History.
While the Magna Carta first used the term, it did not actually become the law of the land until the reign of Edward I of England. It became closely associated with another phrase that helped define the law of the land' due process. During the reign of Edward II the Liberty of Subjects Act of 1354 stated:
 The law of the land and the Liberty of Subjects act remained in use in England. Both were used in colonial charters and common law. They became part of US laws after the American colonies declared their independence from England in 1776.