The first dissidents released by the Cuban authorities as part of a deal to free 52 in total worked as journalists or campaigned for political reforms.
They were arrested in 2003, during what became known as the Black Spring. Some 75 activists were jailed during the crackdown.

Like many Cuban dissidents, the prisoners were adopted by human and media rights groups like PEN, Reporters without Borders and Amnesty International.

Keeping in touch with the prisoners' families and friends, these organisations compiled what little information was to be had about the men locked up in various prisons around the country.

The seven dissidents flown to Spain are:

Ricardo Gonzalez

Journalist Ricardo Gonzalez worked for the independent news agency Cuba Press and was Cuba correspondent for the media rights group Reporters Without Borders.

He also edited the independent fortnightly magazine De Cuba and was one of the founders of the Manuel Marquez Sterling Association in May 2001, an organisation that trains independent journalists.

Mr Gonzalez was arrested in March 2003 and sentenced to 20 years in prison for "being in the pay of the United States" and "undermining Cuba's independence and territorial integrity."

He was jailed in Havana's Combinado del Este prison and has suffered from various health problems, including a heart condition.

In 2008 the media rights group named Mr Gonzalez Reporter of the Year, praising his efforts to help "an independent press survive in Cuba". He turned 60 in February.

Lester Gonzalez Penton

At 26, Lester Gonzalez was the youngest of the dissidents detained in Cuba in March 2003.

The independent journalist was sentenced to 20 years imprisonment and sent to a jail in Santa Clara.

To protest against poor prison conditions Mr Gonzalez went on hunger strike several times, Pen reported.

He had to undergo a hernia operation in 2008 and suffered from chronic gastritis and other health problems, Pen said.

Julio Cesar Galvez

65-year-old Julio Cesar Galvez was one of the journalists, writers and librarians arrested in 2003.

Having worked for official Cuban media organisations for 24 years, he became an independent journalist in 2001.

Mr Galvez was jailed for 15 years and locked up in Havana's Combinado del Este prison, where he suffered from respiratory problems and other ailments, Pen reported.

In 2009 his wife, Irene Viera Silloy, told the Committee to Protect Journalists that her husband was allowed one family visit every two months.

She also said that Mr Galvez continued to write in prison.

Pablo Pacheco Avila

Pablo Pacheco Avila is an independent journalist who worked for two independent news agencies. After his arrest in March 2003 he was sentenced to 20 years in prison.

Pen believes that the 40-year-old's health problems in Moron prison in Ciego de Avila are believed to have included acute gastritis and severe headaches.

In 2009 the dissident received special recognition for his work as a journalist under threat at Amnesty International's Media Awards.

Jose Luis Garcia Paneque

Originally a plastic surgeon, Jose Luis Paneque is said to have been sacked because of his political views. He then became an independent journalist and librarian.

Mr Garcia Paneque was sentenced to 24 years in prison after his arrest in 2003.

The 44-year-old is said to have acute stomach problems, chronic pneumonia and a kidney tumour.

His wife and children reportedly left Cuba for Texas in June 2007 after being harassed by the Cuban authorities.

Omar Moises Ruiz Hernandez

Omar Moises Ruiz Hernandez worked for two independent Cuban news agencies before he was arrested in March 2003 and sentenced to 18 years in prison.

He was also involved in the official Partido Solidaridad Democratica (Democratic Solidarity Party).

Human rights organisations believe that he has been treated badly in Nieves Morejon prison in Guayos and had to spent time in solitary confinement and punishment cells.

Like many of the other dissident prisoners, the 62-year-old is said to suffer from various illnesses, including pneumonia.

Antonio Villarreal

The 59-year-old economist and librarian Antonio Villarreal was involved in the Varela Project, a petition asking for a national referendum on political changes in Cuba.

Mr Villarreal was sentenced to 15 years in prison after his arrest in March 2003.

He is believed to have been in bad health during at least some of his imprisonment in Villa Clara province.