"The Constitution of India is the Supreme Law of India. It lays down the framework defining fundamental political principles, establishes the structure, procedures, powers, and duties of government institutions, and sets out fundamental rights, directive principles, and the duties of citizens. It is the longest written constitution of any sovereign country in the world, containing 448 [Note 1] articles in 22 parts, 12 schedules and 118 amendments. Besides the English version, there is an official Hindi translation. Dr B.R. Ambedkar is widely regarded as the father of the Indian Constitution.
The Constitution was adopted by the Constituent Assembly on 26 November 1949, and came into effect on 26 January 1950. The date 26 January was chosen to commemorate the Purna Swaraj declaration of independence of 1930. With its adoption, the Union of India officially became the modern and contemporary Republic of India and it replaced the Government of India Act 1935 as the country's fundamental governing document. To ensure constitutional autochthony, the constitutional framers inserted Article 395 in the constitution and by this Article the Indian Independence Act, 1947 was repealed.
The Constitution declares India to be a sovereign, socialist, secular, democratic republic, assuring its citizens of justice, equality, and liberty, and endeavours to promote fraternity among them. The words "socialist" and "secular" were added to the definition in 1976 by constitutional amendment(mini constitution). India celebrates the adoption of the constitution on 26 January each year as Republic Day."