The Supreme Court on ruled that coal blocks allocated by the government between 1993 and 2010 were illegal. Following is the chronology of events leading to the judgement:
July 1992: The coal ministry orders setting up of a screening committee to consider proposals from private power companies for captive mining on first-cum-first-serve basis.
Screening committee guidelines give preference to large projects of power and steel companies.
July 14, 1992: A number of coal blocks, which were not in the production plan of Coal India Ltd and the Singareni Collieries Company Limited (SCCL), were identified and a list of 143 blocks were prepared.
1993 to 2010: A total of 70 coal mines or blocks were allocated between 1993 and 2005, 53 in 2006, 52 in 2007, 24 in 2008, 16 in 2009 and one in 2010.
In all, 216 block were allocated between 1993 and 2010, out of which 24 were taken away at different points in time, effectively leaving the total number of allocated blocks at 194.
March 2012: CAG's draft report accuses govt of 'inefficient' allocation of coal blocks 2004-2009; estimates windfall gains to allottees at Rs 10.7 lakh crore.
May 29, 2012: Prime Minister Manmohan Singh offers to give up his public life if found guilty in the scam * May 31, 2012: CVC, based on a complaint of two BJP MPs - Prakash Javadekar and Hansraj Ahir - directs a CBI enquiry.
June 2012: Coal ministry forms an inter-ministerial panel to review the process of allocation of blocks and to decide either on de-allocations or forfeiture of bank guarantees.
Since then, the government has taken back about 80 coal fields while bank guarantees in 42 cases have been forfeited.
August 2012: CAG's final report, tabled in Parliament, tones down loss to exchequer figure to Rs 1.86 lakh crore.
August 25, 2012: Govt claims CAG's presumptive loss theory flawed, no mining yet.
August 27, 2012: PM says CAG flawed; "The observations of the CAG are clearly disputable."
September 6, 2012: PIL in SC seeks cancellation of 194 coal block allotments.
Supreme Court begins monitoring the CBI probe into the coal field allocations
March 2013: The Apex Court asks CBI not to share probe details with govt
April 23, 2013: Standing Committee on Coal and Steel, in a report tabled in Parliament, says coal blocks distributed between 1993-2008 done in unauthorized manner. Says allotment of mines where production not started should be cancelled
April 26, 2013: CBI Director Ranjit Sinha submits affidavit saying investigation report shared with law minister Ashwani Kumar.
May 10, 2013: Ashwani Kumar resigns.
June 11, 2013: CBI registers first information report (FIR) against Naveen Jindal and Dasari Narayana Rao.
October 16, 2013: CBI files an FIR against industrialist Kumar Mangalam Birla and former coal secretary PC Parakh.
July 2014: The Supreme Court sets up a special CBI court to try all coal field allocation cases.
August, 2014: The CBI decides to close its case against Birla and Parakh.