Simon Mann has been in custody since 2004
Former British soldier Simon Mann has been pardoned just a year after being convicted for plotting a coup in Equatorial Guinea.
A presidential adviser said he was being released on humanitarian grounds related to his health. Mann had a hernia operation in 2008.
The ex-Etonian had already spent four years in prison in Zimbabwe for trying to illegally buy weapons before being extradited to the oil-rich former Spanish colony.
Here are the significant events in the development of the case:
7 March - More than 60 mercenaries are arrested in Harare, Zimbabwe.
8 March - Authorities in Equatorial Guinea arrest 15 foreign mercenaries who allegedly came to prepare ground for a coup against President Teodoro Obiang Nguema.
17 March - Men held in Zimbabwe are charged with conspiring to murder President Obiang.
23 August - Fourteen foreign mercenaries (and five local men) go on trial in Malabo, Equatorial Guinea, accused of being an advanced party for the mercenaries held in Zimbabwe.
25 August - Sir Mark Thatcher, 51 - the son of former UK Prime Minister Margaret Thatcher - is arrested at home by South African police in an early morning raid.
He is charged with violating South Africa's anti-mercenary law in connection with an alleged plot to topple the government of Equatorial Guinea.
Sir Mark is later placed under house arrest and protests he is "innocent of all charges" made against him.
27 August - It emerges that the government of Equatorial Guinea has asked for South Africa to extradite Sir Mark.
28 August - Equatorial Guinea says it is seeking international arrest warrants for Sir Mark and other Britons also implicated in the alleged plot.
31 August - The court in Equatorial Guinea suspends proceedings on prosecutors' requests for more information about the alleged role of Mark Thatcher and other British financiers.
1 September - Baroness Thatcher is reported to have posted the two million rand ($334,000) bail for her son who remains under house arrest in Cape Town.
3 September - Sir Mark is freed from house arrest after the bail bond is paid.
Simon Mann's Zimbabwe sentence was reduced from seven to four years
10 September - Harare court sentences British former special services officer Simon Mann to seven years in prison.
The court also hands 16 month sentences to the two pilots of a plane that landed in Zimbabwe carrying the suspected mercenaries. The 65 men who were on the plane, convicted of immigration offences, are given 12-month sentences.
14 November - Equatorial Guinea demands further explanation following UK Home Secretary Jack Straw's parliamentary answer that the UK government had known about the coup plot "in late January 2004".
16 November - Trial of South African Nick du Toit starts in Malabo.
18 November - Equatorial Guinea confirms it has charged Sir Mark in connection with the alleged coup plot.
Sir Mark is accused of having helped finance the coup attempt, according to the country's Attorney General Jose Olo Obono.
24 November - A Cape Town judge rules that Sir Mark will have to answer questions from Equatorial Guinea investigators.
In an interview with Vanity Fair magazine the businessman says he is being "destroyed" by the charges.
He says: "I will never be able to do business again. Who will deal with me?"
26 November - Nick du Toit and Equatorial Guinean opposition leader Severo Moto are found guilty of attempting to oust President Obiang.
Du Toit receives a 34-year jail term and Mr Moto, who is in exile in Spain, is given 63 years in absentia.
13 January - Sir Mark appears in court in South Africa where he pleads guilty over his part in the alleged plot.
Sir Mark had to pay a $500,000 fine - but he denied knowledge of the plot
The businessman, who denies any knowledge of the plot, admits breaking anti-mercenary legislation in South Africa by agreeing to charter a helicopter and agrees a plea-bargain with prosecutors.
He is fined three million rand ($500,000).
Mann's lawyer says his client's sentence in Zimbabwe has been reduced from seven to four years on appeal.
15 May - Zimbabwe frees 62 South Africans more than a year after they were arrested, but South Africa says the next day it will charge them under its strict anti-mercenary laws.
9 May - Mann expects to be released early after his sentence is reduced but a Zimbabwean magistrate rules that he can be extradited to Equatorial Guinea. He appeals.
30 January - Mann is deported to Equatorial Guinea from Zimbabwe to face coup plot charges after losing an appeal against extradition. He had served four years for buying weapons without a licence.
He is flown to Equatorial Guinea and taken to Black Beach prison. His lawyers insist he was illegally removed by being moved in secret before an appeal process was finished. The Foreign Office protests.
11 March - Mann says he plotted to oust Equatorial Guinea's president, but the scheme failed.
28 March - Equatorial Guinea issues an arrest warrant for Sir Mark.
30 March - Guinea's public prosecutor says that Mann has testified that Sir Mark knew all about the scheme to overthrow President Obiang.
17 June - Mann goes on trial and the prosecution asks he be jailed for 32 years for his role in the coup plot. During the trial, he says Sir Mark was part of the plot.
20 June - On the last day of his trial, Mann requests leniency, saying he was sorry for having been part of the plot.
7 July - Mann is sentenced to 34 years and four months in jail by an Equatorial Guinea court for his role in the plot.
18 February - An armed group launches an attack on the presidential palace in Malabo, the capital of Equatorial Guinea. President Obiang was not in residence at the time.
State media said the gunmen involved were from a Nigerian rebel group - and 15 people were arrested in connection with the attack.
There was speculation that it might have been an attempt to rescue British mercenary Mann.
3 November - Equatorial Guinea's government pardons Mann, du Toit and three other South Africans on humanitarian grounds.
An adviser to the president, Miguel Mifuno, tells the BBC Mann has to leave the country within 24 hours.