Following is the chronology of events in the 2G spectrum scam case:
May, 2007: DMK leader A Raja takes over as Telecom Minister.
August, 2007: The Department of Telecommunications (DoT) initiates process of allotment of 2G spectrum for telecom along with Universal Access Service (UAS) Licences.
November 2, 2007: The Prime Minister writes to Raja directing him to ensure allotment of 2G spectrum in a fair and transparent manner and to ensure that licence fee was properly revised. Raja writes back to the Prime Minister rejecting many of his recommendations.
2009: Central Vigilance Commission (CVC) directs CBI to investigate the irregularities in allocation of 2G spectrum.
October 21, 2009: CBI registers a case and files an FIR against "unknown officers" of DoT and unknown private persons/companies under various provisions of IPC and Prevention of Corruption Act.
May 6, 2010: Telephonic conversation between Raja and corporate lobbyist Niira Radia made public by the media.
September 13, 2010: Supreme Court asks government and A Raja to reply within 10 days to three petitions filed by an NGO and others alleging there was a Rs 70,000 crore scam in the grant of telecom licences in 2008.
November 10, 2010: The Comptroller and Auditor General (CAG) submits report on 2G spectrum to government stating loss of Rs 1.76 lakh crore to exchequer.
November 14, 2010: Raja resigns as Telecom Minister.
November 25, 2010: Supreme Court ticks off CBI for not questioning Raja.
December 1, 2010: Supreme Court directs original tapes containing conversation between corporate lobbyist Niira Radia and others be handed over to it.
December 2, 2010: Government places recorded tapes in the Supreme Court.
December 8, 2010: Supreme Court asks Centre to consider setting up of a special court to try 2G spectrum scam case.
February 2, 2011: A Raja, former Telecom Secretary Siddartha Behura and Raja's former Personal Secretary R K Chandolia arrested, remanded to CBI custody next day.
February 8, 2011: Shahid Usman Balwa, promoter of Swan Telecom, arrested by CBI.
February 17, 2011: Raja sent to Tihar Jail under judicial custody.
February 18, 2011: Balwa sent to judicial custody.
March 14, 2011: The Delhi High Court sets up special court to deal exclusively with 2G cases.
March 29, 2011: Shahid Balwa's brother Asif and Kusegaon realties' executive Rajeev Agarwal arrested.
April 2, 2011: CBI files its first chargesheet.
April 25, 2011: CBI files second chargesheet and court issues summons to DMK chief M Karunanidhi's daughter Kanimozhi, Managing Director of Kalaignar TV Sharad Kumar (Kanimozhi and her mother have major stakes in the channel) and Cineyug Films' director Karim Morani taking congizance of the chargesheet.
May 6, 2011: Kanimozhi and Sharad Kumar file bail plea while Karim Morani seeks exemption from appearance.
May 20, 2011: Court rejects bail pleas of Kanimozhi and Sharad Kumar, and orders their forthwith arrest.
June 20, 2011: Supreme Court rejects Kanimozhi's bail plea.
July 25, 2011: Arguments on charges begin.
October 9, 2011: CBI files FIR against another DMK leader and former telecom minister Dayanidhi Maran and his brother.
October 22, 2011: Court put on trial all 17 accused.
November 3, 2011: Trial court rejects bail plea of Kanimozhi and seven others.
November 5, 2011: Kanimozhi and others moves bail in Delhi High Court.
November 23, 2011: Supreme Court grants bail to five telecom executives - Unitech Wireless' former MD Sanjay Chandra, Swan Telecom's Director Vinod Goenka and Reliance Anil Dhirubhai Ambani Group's executives Hari Nair, Gautam Doshi and Surendra Pipara. They were charged with criminal conspiracy cause criminal breach of trust by a public servant.
November 28, 2011: Delhi High Court grants bail to Kanimozhi, Sharad Kumar, Karim Morani, Asif Balwa and Rajeev Agarwal; reserves bail plea of Siddharth Behura.
December 8, 2011: Janata Party chief Subramanian Swamy allowed to testify in support of his private complaint seeking prosecution of Union Home Minister P Chidambaram in the 2G case by a Delhi court.
January 7, 2012: Mr Swamy submits certified copies of documents and concludes his arguments. Court lists Swamy's application for arguements on January 21.
January 21, 2012: Delhi court reserves its order for February 4 on Janata Party chief Subramanian Swamy's plea seeking prosecution of Union Home Minister P Chidambaram in the 2G scam case.
February 2, 2012: The Supreme Court will deliver three important verdicts on the telecom scam. Justices GS Singhvi and AK Ganguly will announce whether Home Minister P Chidambaram should be investigated by the CBI, which is handling the telecom or 2G scam.
May 9, 2012: Supreme Court grants bail to former telecom secretary Siddharth Behura. Within an hour, A Raja applies for bail.
May 11, 2012: Special CBI judge OP Saini reserves order on A Raja's bail plea
May 15, 2012: Special CBI court grants former telecom minister A Raja bail after 15 months in jail.