The idea of a Constituent Assembly for India was first proposed by M.N. Roy in 1934. It was officially demanded by the Indian National Congress in 1935 and accepted in principle by the British government through the August Offer of 1940. The assembly was finally constituted in November 1946 under the scheme formulated by the Cabinet Mission Plan.

• First Meeting: December 9, 1946. Dr. Sachchidananda Sinha was elected as the temporary/interim President of the Assembly, following French practice (senior-most member).
• Permanent President: On December 11, 1946, Dr. Rajendra Prasad was elected as President, and H.C. Mukherjee was elected as Vice-President. Sir B.N. Rau was appointed as the Constitutional Advisor to the Assembly.
• Objective Resolution: Moved by Jawaharlal Nehru on December 13, 1946, which later became the Preamble of the Constitution. It was unanimously adopted on January 22, 1947.
• Time Taken: The Assembly took 2 years, 11 months, and 18 days to draft the Constitution, holding 11 sessions.
• Drafting Committee: Appointed on August 29, 1947, consisting of 7 members, with Dr. B.R. Ambedkar as the Chairman (celebrated as the Father of the Indian Constitution).
• Adoption & Enforcement: The Constitution was adopted on November 26, 1949 (observed as Constitution Day / Samvidhan Divas). It originally contained 395 Articles, 22 Parts, and 8 Schedules. It came into force on January 26, 1950 (celebrated as Republic Day), which was selected because on that day in 1930, the Purna Swaraj declaration was made.

The Indian Constitution has drawn its features from various global constitutions as well as the Government of India Act of 1935. Dr. B.R. Ambedkar proudly stated that it was framed after "ransacking all the known Constitutions of the world":

Visualizing the major democratic models and features adapted into the Indian Constitution from other countries.

• Government of India Act 1935: Federal scheme, office of Governor, Judiciary, Public Service Commissions, Emergency provisions, and administrative details.
• British Constitution (UK): Parliamentary form of government, Rule of Law, legislative procedure, Single Citizenship, cabinet system, legislative writs, bicameralism.
• United States Constitution (US): Fundamental Rights, independence of judiciary, Judicial Review, impeachment of the President, removal of Supreme Court and High Court judges, office of Vice-President.
• Irish Constitution: Directive Principles of State Policy (DPSP), nomination of members to Rajya Sabha, method of election of the President.
• Canadian Constitution: Federation with a strong Centre, vesting of residuary powers in the Centre, appointment of state governors by the Centre, advisory jurisdiction of the Supreme Court.
• Australian Constitution: Concurrent List, freedom of trade, commerce and intercourse, joint sitting of the two Houses of Parliament.
• Weimar Constitution of Germany: Suspension of Fundamental Rights during Emergency.
• Soviet Constitution (USSR / Russia): Fundamental Duties, ideal of justice (social, economic, and political) in the Preamble.
• French Constitution: Republic, ideals of liberty, equality, and fraternity in the Preamble.
• South African Constitution: Procedure for amendment of the Constitution, election of members of Rajya Sabha.

The Preamble

The Preamble serves as an introductory statement outlining the goals and values of the Constitution. It declares India to be a Sovereign, Socialist, Secular, Democratic, Republic.

The Preamble has been amended only once, by the 42nd Constitutional Amendment Act of 1976, which added three new words: Socialist, Secular, and Integrity.

The 12 Schedules

Schedules are additional lists that categorize administrative details. Candidates can use the popular mnemonic "TEARS OF OLD PM" to memorize the 12 schedules in order:

1. T - Territories: Names of States and Union Territories with their territorial jurisdictions.
2. E - Emoluments: Provisions relating to salaries, allowances, and privileges of President, Governors, Speaker, Judges, etc.
3. A - Affirmations/Oaths: Oaths and affirmations for Union ministers, MPs, Judges, CAG.
4. R - Rajya Sabha: Allocation of seats in the Rajya Sabha (Council of States) to States and Union Territories.
5. S - Scheduled Areas: Administration and control of scheduled areas and scheduled tribes.
6. O - Other Areas: Administration of tribal areas in the northeastern states: Assam, Meghalaya, Tripura, and Mizoram (Mnemonic: ATM without Money - Assam, Tripura, Meghalaya, Mizoram).
7. F - Federal List: Distribution of legislative powers (Union List, State List, Concurrent List).
8. O - Official Languages: 22 recognized official languages (originally 14). Sindhi was added by the 21st Amendment, Konkani, Manipuri, and Nepali by the 71st, and Bodo, Dogri, Maithili, and Santhali by the 92nd.
9. L - Land Reforms: Acts and regulations relating to land reforms (Added by the 1st Amendment of 1951 to shield laws from judicial review).
10. D - Defection: Provisions relating to disqualification of members on ground of defection (Added by the 52nd Amendment of 1985).
11. P - Panchayats: Powers, authority, and responsibilities of Panchayats (Contains 29 matters; added by the 73rd Amendment of 1992).
12. M - Municipalities: Powers, authority, and responsibilities of Municipalities (Contains 18 matters; added by the 74th Amendment of 1992).