Constitution of India

The Constitution of India is the supreme legal document of India, and the longest written national constitution in the world. The document lays down the framework that demarcates fundamental political code, structure, procedures, powers, and duties of government institutions and sets out fundamental rights, directive principles, and the duties of citizens.

It espouses constitutional supremacy (not parliamentary supremacy found in the United Kingdom, since it was created by a constituent assembly rather than Parliament) and was adopted with a declaration in its preamble. The Indian Constitution does not contain a provision to limit the powers of the parliament to amend the constitution. However, the Supreme Court in Kesavananda Bharati v. State of Kerala held that there were certain features of the Constitution so integral to its functioning and existence that they could never be cut out of the constitution (known as the 'Basic Structure' Doctrine).

The Government of India Act 1935, mainly drafted by Samuel Hoare, provided the basis for the constitution of India. The Constituent Assembly of India adopted the constitution on 26 November 1949 and became effective on 26 January 1950. It became the country's fundamental governing document, and the Dominion of India became the Republic of India. To ensure constitutional autochthony, its framers repealed prior acts of the British parliament, in Article 395. India celebrates its constitution on 26 January as Republic Day.

The constitution declares India a sovereign, socialist, secular, and democratic republic, assures its citizens justice, equality, and liberty, and endeavours to promote fraternity. The original 1950 constitution is preserved in a nitrogen-filled case at the Parliament Library Building in New Delhi.