The case of Libyan Abdelbaset Ali al-Megrahi has been a complex one since the day he was indicted on 270 counts of murder in November 1991.
Ten years later he was found guilty of killing the people who died when Pan Am Flight 103 exploded over Lockerbie.
Megrahi, who has always proclaimed his innocence, unsuccessfully appealed against his conviction. But he was subsequently allowed to return home after it emerged that he had terminal cancer.
1 SEPTEMBER 2009
UK ministers release documents recording their correspondence over the fate of Lockerbie bomber Abdelbaset Ali al-Megrahi. The Scottish Government also releases further documents relating to the case.
24 AUGUST 2009
The Scottish Parliament is recalled to discuss the release of the Lockerbie bomber. Justice Secretary Kenny MacAskill faces questioning over his decision from MSPs.
20 AUGUST 2009
The Scottish government releases Megrahi on compassionate grounds. He returns home to Libya aboard a jet belonging to Libyan leader Muammar Gaddafi.
18 AUGUST 2009
Judges accept an application by the Lockerbie bomber to drop his second appeal against conviction.
The permission of the High Court in Edinburgh was required before the proceedings by Abdelbaset Ali al-Megrahi could be formally abandoned.
13 AUGUST 2009
Lawyers for Abdelbaset Ali al-Megrahi say he has applied to abandon his second appeal against his conviction.
12 AUGUST 2009
Magrahi is likely to be released from prison on compassionate grounds, the BBC learns.
25 JULY 2009
The man convicted of the Lockerbie bombing asks to be released from jail on compassionate grounds due to his illness.
6 MAY 2009
The Libyan authorities request Megrahi be moved from Scotland under the terms of a prisoner transfer agreement.
28 APRIL 2009
The legal team for the man convicted of the Lockerbie bombing tells judges that the evidence against him was "wholly circumstantial".
21 DECEMBER 2008
Relatives of the 270 people killed in the Lockerbie bombing mark the 20th anniversary of the tragedy.
14 NOVEMBER 2008
A court rules that the Lockerbie bomber, Abdelbaset Ali al-Megrahi, will remain in jail while he appeals against his conviction.
31 OCTOBER 2008
The father of one of the victims of the Lockerbie bombing reiterates his call for Megrahi to be released. Jim Swire criticised the slow appeal process faced by the man convicted of the attack and said the question of whether Megrahi should be released was one of "common humanity".
30 OCTOBER 2008
Megrahi applies to be released on bail, pending the appeal against both his conviction and sentence. Jim Swire, whose daughter died in the Lockerbie bombing, says keeping Megrahi behind bars while he battles cancer "would amount to exquisite torture".
21 OCTOBER 2008
Megrahi's lawyer reveals the 56-year-old former Libyan intelligence agent has been diagnosed with "advanced stage" prostate cancer.
15 OCTOBER 2008
The Lockerbie bomber has won the latest round of his long-running legal battle to overturn his conviction.
3 APRIL 2008
The US state department has said it is standing by an international agreement requiring the Lockerbie bomber to serve his sentence in Scotland.
7 MARCH 2008
The man convicted of the Lockerbie bombing has failed in his latest attempt to persuade judges that secret documents should be handed over.
2 FEBRUARY 2008
Scotland's first minister has asked for assurances that the Lockerbie bomber will be excluded from any prisoner transfer deal with Libya.
2 OCTOBER 2007
Lawyers acting for the Lockerbie bomber are expected to ask the High Court to examine claims that vital documents were kept from the trial defence team.
28 JUNE 2007
The Scottish Criminal Cases Review Commission, which has been investigating the case since 2003, recommends that Abdelbaset Ali Mohmed al-Megrahi is granted a second appeal against his conviction.
7 JUNE 2007
The UK Government publishes details of a deal struck with Libya on prisoner exchange, which it insists does not cover the Lockerbie bomber's case.
8 JUNE 2006
Appeal court judges are asked to delay challenges to the Lockerbie bomber's 27-year prison term.
The Libyan's legal team asked judges to put the challenges on hold until the Scottish Criminal Cases Review Commission looks at the case.
24 FEBRUARY 2005
The Lockerbie bomber is moved from a purpose-built jail unit in Glasgow to another prison 25 miles away in Greenock.
31 MAY 2004
Abdelbaset Ali Mohmed al-Megrahi begins a challenge against the 27-year punishment period of his jail term.
18 DECEMBER 2003
The lord advocate lodges an appeal against the sentence imposed on the man convicted of the Lockerbie bombing.
He argues that the punishment part of the sentence is unduly lenient.
24 NOVEMBER 2003
Megrahi is told he must serve at least 27 years in jail.
His sentence was increased after a change in the law meant he had to again come before the Scottish courts so that the punishment period could be set.
23 SEPTEMBER 2003
The Lockerbie bomber lodges a fresh appeal against his conviction.
The Scottish Criminal Cases Review Commission is asked to investigate the case of Abdelbaset Ali Mohmed al-Megrahi.
The commission is an independent body charged with investigating possible miscarriages of justice.
14 AUGUST 2003
Lawyers acting for families of the Lockerbie bombing victims say they have reached agreement with Libya on the payment of compensation.
The deal to set up a $2.7bn (£1.7bn) fund was struck with Libyan officials after negotiations in London.
10 JUNE 2002
Prime Minister Tony Blair rules out moving the Libyan convicted of the Lockerbie bombing from a Scottish prison.
10 JUNE 2002
Nelson Mandela calls for the man convicted of the Lockerbie bombing to be moved to a Muslim country.
15 MARCH 2002
Abdelbaset Ali Mohmed al-Megrahi spends his first night at a prison in Glasgow where he will serve the rest of his life sentence.
He was flown by helicopter to HMP Barlinnie.
14 MARCH 2002
The Libyan man found guilty of the Lockerbie bombing loses his appeal against the conviction.
23 JANUARY 2002
Five senior Scottish judges begin hearing an appeal by the man convicted of the 1988 Lockerbie bombing.
7 FEBRUARY 2001
As expected, Megrahi lodges an appeal against his conviction at the start of another lengthy legal process.
31 JANUARY 2001
Abdelbaset Ali Mohmed al-Megrahi is found guilty of murder after the historic trial under Scottish law in the Netherlands.
The judges recommend a minimum of 20 years "in view of the horrendous nature of this crime".
Megrahi's co-accused, Al Amin Khalifa Fhimah, is found not guilty and told he is free to return home.
3 MAY 2000
The trial of Abdelbaset Ali Mohmed al-Megrahi, 48, and Al Amin Khalifa Fhimah, 44, opens at Camp Zeist, a specially convened Scottish court sitting in the Netherlands.
The trial is expected to run for more than a year.
A Scottish judge agrees to delay the trial for six months.
5 APRIL 1999
The suspects are taken into Dutch custody after flying from Tripoli to an airbase near the Hague and are formally charged with the bombing.
UN sanctions against Libya are suspended as agreed.
19 MARCH 1999
Nelson Mandela flies to Tripoli with special UN permission to speak to Colonel Gaddafi.
He says that the Lockerbie suspects will be surrendered on or before 6 April.
UN Secretary General Kofi Annan meets Libyan leader Colonel Gaddafi to urge Libya to hand over the bombing suspects.
Britain and the United States propose trying the suspects in the Netherlands under Scottish law.
Libya confirms it would accept a trial in a neutral country, operating under Scottish law.
15 APRIL 1992
The UN Security Council imposes sanctions on air travel and arms sales over Libya's refusal to hand the suspects over for trial in a Scottish court.
13 NOVEMBER 1991
US and British investigators indict Libyans Abdelbaset Ali Mohmed al-Megrahi and Al Amin Khalifa Fhimah on 270 counts of murder, conspiracy to murder and violating Britain's 1982 Aviation Security Act.
The men were accused of being Libyan intelligence agents.
21 DECEMBER 1988
Pan Am Flight 103 from London to New York explodes 31,000ft over Lockerbie, 38 minutes after take-off from London.
The 259 people on board the Boeing 747 are killed, along with 11 people on the ground.