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[1] written constitution of any sovereign country in the world, containing 444[Note 1] articles in 22 parts, 12 schedules and 118 amendments. Besides the Hindi version, there is an official English translation. Dr. Bhimrao Ramji Ambedkar is widely known as the father of the Indian Constitution.

The Constitution follows parliamentary system of government and the executive is directly accountable to legislature. Article 74 provides that there shall be a Prime Minister of India as the head of government. It also states that there shall be a President of India and a Vice-President of India under Articles 52 and 63. Unlike the Prime Minister, the President largely performs ceremonial roles. The Constitution is federal in nature. Each State and each Union territory of India has their own government.

Analogues to President and Prime Minister, is the Governor in case of States, Lieutenant Governor for Union territories and the Chief Minister. The 73rd and 74th Amendment Act also introduced the system of Panchayati raj in villages and municipalities. Also Article 370 of the Constitution gives special status to the State of Jammu and Kashmir. The Constitution was adopted by the Constituent Assembly on 26 November 1949, and came into effect on 26 January 1950. [2] 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 framers of constitution inserted Article 395 in the constitution and by this Article the Indian Independence Act, 1947 was repealed. [3]The Constitution declares India to be a sovereign, socialist,secular, democratic republic, assuring its citizens of justice, equality, and liberty, and endeavors to promote fraternity among them. 4] The words "socialist" and "secular" were added to the definition in 1976 by constitutional amendment (mini constitution). [5] India celebrates the adoption of the constitution on 26 January each year asRepublic Day.

[6] The major portion of the Indian subcontinent was under British colonial rule from 1857 to 1947. The impact of economic, political and social exploitation during this period helped the gradual rise of the Indian independence movement to gain independence from foreign rule.The movement culminated in the formation of the Dominion of India on 15 August 1947, along with the Dominion of Pakistan. The Constitution of India was adopted on 26 November 1949 and came into effect on 26 January 1950, proclaiming India to be a sovereign, democratic republic. It contained the founding principles of the law of the land which would govern India after its independence from British rule. On the day the constitution came into effect, India ceased to be a dominion of the British Crown.

The Indian constitution is the world's longest constitution. At the time of commencement, the constitution had 395 articles in 22 parts and 8 schedules. It consists of almost 80,000 words and took 2 years 11 months and 18 days to build. In the United Kingdom the office of the Secretary of State for India was the authority through whom Parliament exercised its rule (along with the Council of India), and established the office of Viceroy of India(along with an Executive Council in India, consisting of high officials of the British Government).

The Indian Councils Act 1861 provided for a Legislative Council consisting of the members of the Executive council and non-official members. The Indian Councils Act 1892 established provincial legislatures and increased the powers of the Legislative Council. Although these Acts increased the representation of Indians in the government, their power still remained limited. The Indian Councils Act 1909 and the Government of India Act 1919 further expanded participation of Indians in the government.

The Indian Independence Act, passed by the British Parliament on 18 July 1947, divided British India into two new independent states, India and Pakistan, which were to be dominions under theCommonwealth of Nations until they had each finished drafting and enacted a new constitution. The Constituent Assembly was divided into two for the separate states, with each new Assembly having sovereign powers transferred to it for the respective dominion.The Act also terminated British suzerainty over the princely states, each of which was left to decide whether to accede to one or other of the new dominions or to continue as independent states in their own right. However, in most cases the states were so dependent on central institutions that they were widely expected to accede to a dominion.

When the Constitution of India came into force on 26 January 1950, it repealed the Indian Independence Act. India ceased to be a dominion of the British Crown and became a sovereign democratic republic. 26 November 1949 is also known as National Law Day.