Two sets of proceedings carry this name and they are twenty years apart.
The first, from 1915, tried the Ghadar returnees under a special tribunal set up by ordinance, without appeal. Two hundred and ninety-one were accused across the supplementary cases. Forty-two death sentences were passed and about twenty carried out, including Kartar Singh Sarabha Ji, Vishnu Ganesh Pingle and Bhai Balwant Singh of Khurdpur.
The second, from 1929, tried Bhagat Singh, Sukhdev, Rajguru and their associates for the killing of the police officer John Saunders and for the Assembly bomb. It was also conducted by a special tribunal set up by ordinance, also without appeal.
The hunger strike inside that second case, over the treatment of political prisoners, ran 116 days for Bhagat Singh. Jatindranath Das died on the 63rd day of his own strike in September 1929. The strike changed jail rules across India.
Bhagat Singh, Sukhdev and Rajguru were hanged at Lahore on 23 March 1931, a day early and in the evening, and the bodies were taken out through a hole in the jail wall and burned at Hussainiwala on the Sutlej.
Both tribunals used the same legal instrument, an ordinance removing appeal. That is the through-line between the two cases and it is rarely stated.
The 1915 tribunal sat inside Lahore Central Jail. The accused had no appeal to any court and the sentences were confirmed by the provincial government rather than by a judge.
The defence in 1929 turned the courtroom into a platform. The accused refused to recognise the tribunal, shouted slogans, and gave statements the newspapers printed until reporting of the case was restricted.
The ordinance constituting the 1930 tribunal lapsed before the sentences were carried out, which is one of the grounds on which the executions have been argued to be unlawful ever since.