I would like to point out that linguistically there is no language called Hindi. The modern Hindi is a Sankritized, modernized register of the Hindustani language - http://en.wikipedia.org/wiki/Hindustani_language
I am not sure if somebody amalgamated all those languages to form Hindi in 1947. The original article 343 of the Indian constitution specified Hindi in Devnagri as the national language, mostly out of the insistence of people like Gopal Krishna Goghale who while agreeing that English is a better language for law-making (http://www.constitution.org/cons/india/p17348.html) argued that we should not declare it the national language because of the colonial past.
The Official Languages Act of 1963 and subsequent amendments to article 343 cleaned up this mess.
Edit: Clarified the correct article of the constitution. I originally said Article XVII, but it should have been Part XVII.
I am not sure if somebody amalgamated all those languages to form Hindi in 1947. The original article 343 of the Indian constitution specified Hindi in Devnagri as the national language, mostly out of the insistence of people like Gopal Krishna Goghale who while agreeing that English is a better language for law-making (http://www.constitution.org/cons/india/p17348.html) argued that we should not declare it the national language because of the colonial past.
The Official Languages Act of 1963 and subsequent amendments to article 343 cleaned up this mess.
Edit: Clarified the correct article of the constitution. I originally said Article XVII, but it should have been Part XVII.