The basic principles, laws, and fundamental ideologies that formulate the nature and function of a government can be termed as Constitutional Laws.
The Magna Carta (1215) was the first ever effort to establish the concept of Constitutional Laws.
The term ‘Constitutional Laws’ was first used in a political sense after the Revolution of 1688 in Britain, when the then monarch, James II, was accused of violating the constitution of the land. However, the British Constitution is an unwritten document which is actually a combination of numerous Acts of the Parliament and various judicial decisions.
In US, the Constitutional Law is the product of judicial interpretations of the US Constitution in respect to the matters that are decided by the courts. In US, the Constitutional Laws interprets the US Constitution and provides the means of implementation of the same. It describes the relationship between the state and federal governments and deals with fundamental rights and other aspects of sources and application of government authority. It also establishes three branches of the federal government and specifies their powers.
In India, the Constitutional Laws is based on the Western legal principle of liberal democracy. Indian Constitution has adopted several features like Parliamentary form of Government, power of judicial review, directive principles of state policy, concepts of liberty, equality and fraternity, fundamental duties and emergency provisions from different constitutions of the world.
Modern Constitutional Laws has developed from the principle that the state must protect certain fundamental rights of the individual. As the number of free states has multiplied, it has led to the incorporation of various constitutions and this has contributed in the development of Constitutional Laws