Mr Boumediene had been on hunger strike since December 2006
An Algerian man held for seven years by the US has arrived in France after being set free from Guantanamo Bay.
Lakhdar Boumediene was held in Bosnia in 2001, but was cleared last year of any wrongdoing and cleared for release.
He won a landmark Supreme Court case granting Guantanamo inmates the right to challenge their confinement.
The release comes on the same day that US President Barack Obama announced that he was reviving military trials for some detainees.
Earlier this month, France offered to accept Mr Boumediene, 42, after he was cleared of any wrongdoing in November by a US judge who ruled he had been illegally detained.
Mr Boumediene was flown from the US naval base in south-eastern Cuba to waiting relatives in France.
He had been on hunger strike since December 2006 and was force-fed twice a day through a nose-drip, the AFP news agency reported.
His wife and two daughters, who went to Algeria after his arrest, will also be taken in by France, it said.
Mr Boumediene was among six men arrested in Bosnia in 2001 and charged with plotting to attack the US embassy in Sarajevo. They were formally exonerated by Bosnian prosecutors in 2004.
All six said they were subjected to harsh interrogation techniques at Guantanamo, which involved prolonged isolation, forced nudity, and sleep deprivation.
Mr Boumediene was one of two detainees who won a case before the US Supreme Court last June on behalf of 37 foreign nationals at the US-run prison camp.
The ruling gave Guantanamo prisoners the long-standing habeas corpus right to challenge their detention in US civilian courts.
Since then, federal judges have ordered the release of 25 prisoners, including three of Mr Boumediene's fellow Algerian nationals.
The men were transferred to their adoptive home of Bosnia in December, becoming the first Guantanamo inmates to be released by the former Bush administration under a judge's orders.