This was the first US war crimes trial since World War II
Osama Bin Laden's former driver has been sentenced to five-and-a-half years in prison at the first US military trial in Guantanamo Bay.
Salim Hamdan was convicted on Wednesday of supporting terrorism, but acquitted of conspiracy to murder.
Prosecutors had demanded a sentence of not less than 30 years.
On time served Hamdan could be released in five months but the Pentagon has said he will still be retained as an "enemy combatant".
The US has always argued it can detain such people indefinitely, as long as its so-called war on terror continues.
The Pentagon said Hamdan would serve his sentence and then be eligible for review.
The BBC's Kim Ghattas at the trial says the sentence is a dramatic snub to the Bush administration and came after just one-and-a-half hours of deliberation.
The jury of six US military officers, not the judge, imposed the sentence under the tribunal rules.
"It is my duty as president [of the jury] to inform you that this military commission sentences you to be confined for 66 months," a juror told Hamdan.
Conspiracy: Not guilty of two counts of conspiring with al-Qaeda to attack civilians, destroy property and commit murder
Providing support for terrorism: Guilty on five counts, including being the driver and bodyguard for Osama Bin Laden, a man he knew to be the leader of a terrorist group. Not guilty on three other counts
Our correspondent says Hamdan looked nervous as he walked in for sentencing but after hearing it, he told jurors: "I would like to apologise one more time to all the members and I would like to thank you for what you have done for me."
The judge, Navy Capt Keith Allred, told Hamdan: "I hope the day comes when you return to your wife and your daughters and your country."
Hamdan, who is aged about 40, smiled as he left court and said thank you to those in the room.
After the sentencing, Pentagon spokesman Bryan Whitman said: "He will serve out the rest of his sentence. At that time he will still be considered an enemy combatant.
"But he will be eligible for review by an Administrative Review Board."
The boards decide annually on the threat posed by detainees and the possibility of their transfer or release.
The White House had earlier said the trial was "fair".
The defence is still likely to go ahead with the appeal it announced on Wednesday.
Rights groups have condemned the tribunal system. Amnesty International said it was "fundamentally flawed" and should be abandoned.
'Worked for wages'
In his earlier plea for leniency to the jury, Hamdan said in a prepared statement: "It's true there are work opportunities in Yemen, but not at the level I needed after I got married and not to the level of ambitions that I had in my future."
He said he regretted the loss of "innocent lives".
Hamdan had admitted working for Bin Laden in Afghanistan from 1997 to 2001 for $200 (£99) a month, but said he worked for wages, not to wage war on the US.
About 270 suspects remain in detention in Guantanamo Bay.
Among the dozens of other inmates due to be tried there in the coming months are men accused of plotting the 9/11 attacks.