Section 377 refers to 'unnatural offences.' It says a person voluntarily having carnal intercourse against the order of nature with any man, woman or animal, shall be punished with imprisonment for life.
It was introduced in 1861 during the British rule of India and was modelled on the Buggery Act of 1533. It criminalizes sexual activities 'against the order of nature,' including homosexual activities.
Section 377 was first raised by Naz Foundation, an NGO, and AIDS Bedhbhav Virodh Andolan, in the Delhi HC in 2001. Both the petitions were dismissed.
In July 2009, the section was read down with respect to sex between consenting adults by the Delhi HC.
But in 2013, the judgement was overturned by the SC that amending or repealing section 377 should be a matter left to Parliament, not the judiciary.
In January 2018, a three-member SC bench heard a petition filed by five people asking the SC to revisit the Naz Foundation judgment.
On 10 July 2018, a five-member constitutional bench of the SC commenced hearing of the pleas challenging the constitutionality of section 377.
On 6th September 2018, SC scrapped section 377 with all the 5 members of the bench agreeing unanimously.