The Constitution of India was amended for the first time in

Article 368 of the Constitution of India lays down the procedure by which Parliament can amend the Constitution. Each amendment enacted through this procedure is recorded as a numbered 'Constitution (Amendment) Act', and it takes legal effect from the date it receives the President's assent.

The very first amendment made to the Constitution of India is the Constitution (First Amendment) Act, 1951. It was piloted through the provisional Parliament - India's first general elections had not yet been held - to address difficulties the courts had raised over early land-reform legislation and the scope of certain fundamental rights. Its main changes were:

• Adding reasonable restrictions - on grounds such as public order, incitement to an offence, and relations with foreign states - to the freedom of speech and expression under Article 19(1)(a), via a revised Article 19(2).

• Amending Article 19(6) to let the State create or expand its own monopoly, wholly or partly, in any trade, business, industry or service.

• Inserting Article 15(4), allowing the State to make special provisions for the advancement of socially and educationally backward classes.

• Inserting Article 31-A, protecting laws on the acquisition of estates and related agrarian reforms from being challenged on specified fundamental-rights grounds.

• Inserting the Ninth Schedule (through Article 31-B) to shield specified land-reform and zamindari-abolition laws from being challenged as violating fundamental rights.

• Making consequential changes to Articles 85, 87, 174, 176, 341, 342, 372 and 376.

This Bill completed its passage through the provisional Parliament and received the President's assent on 18 June 1951, so the Constitution (First Amendment) Act, 1951 is dated June 1951 - the correct answer. Official records, including the Ministry of Law and Justice's gazetted text of the Act and constitutional-law compilations such as the Bombay High Court's table of constitutional amendments, both record 18 June 1951 as the date of enactment. This also confirms that January 1951 is too early (the Bill had not yet been introduced) and that June/July 1952 are too late - by then India's first general elections of 1951-52 were over and the first elected Lok Sabha, constituted in April 1952, had already taken over parliamentary business, so the First Amendment predates that Parliament.