We're used to seeing them either training or in action in some of the world's trouble spots, but today marines from 42 commando, based in Plymouth, had a very different role.
They were providing sentries outside Buckingham Palace - and that meant changing the guard in front of thousands of tourists. Bob Constantine reports:
Royal Marines from Plymouth are helping guard Buckingham Palace.
Men from kilo company, Four-Two Commando, have swapped their usual camouflage for full dress uniform as they patrol the railings outside the royal residence.
It's to mark the corps' 350th anniversary and is only the fourth time in a hundred years they've taken on the ceremonial duties.
The Royal Marines of Taunton-based 40 Commando have been flexing their muscles on exercise in Cornwall.Read the full story ›
A former Royal Marine from Taunton, who was found guilty of murdering an injured insurgent in Afghanistan, has lodged an appeal application in a bid to challenge his conviction.
39 year old Sergeant Alexander Blackman was jailed for a minimum of 10 years in December.
The naming of two Royal Marines who were acquitted of the murder of an injured insurgent in Afghanistan comes after one of their colleagues was given a life sentence for the killing.
Marine A, who was later named as Alexander Blackman, will spend at least 10 years in prison for the murder, which was filmed on the headcam of a comrade during a patrol in Afghanistan.
Blackman said he was "devastated" at being given a life sentence and was "very sorry" for his actions.
The two Marines acquitted of the murder were named as Corporal Christopher Glyn Watson and Marine Jack Alexander Hammond today after the High Court lifted an anonymity order.
Two Royal Marines who were acquitted of the murder of an injured insurgent in Afghanistan can be named for the first time as Corporal Christopher Glyn Watson and Marine Jack Alexander Hammond.
The High Court confirmed that an anonymity order preventing publication of their identities has been lifted.
The country's top judge has explained the reasoning behind a ruling allowing the public naming of a Royal Marine from Taunton who murdered an Afghan insurgent.
Lord Chief Justice Lord Thomas and two other judges at the High Court in London made the ruling.
It led to the identity of Sergeant Alexander Blackman (previously known only as Marine A) being revealed.
Giving the court's reasons for reaching its decision, Lord Thomas said the balance came "very firmly down on the side of open justice".
The case is of the greatest public interest, involving as it does a unique charge of murder against soldiers on military operations against a wounded detainee.
There is, therefore, the greatest public interest in the whole of the proceedings being publicly reported.
(In the case of Marine A) there is the greatest public interest in knowing who he was and his background, given his conviction.
It would require an overwhelming case if a person convicted of murder in the course of an armed conflict were to remain anonymous.
Lord Thomas said that "as against that", there is the risk that Blackman would be attacked in prison and after his release from the life sentence.
The prison authorities will be well aware of that risk and take steps to minimise it, as they do for other offenders at risk of attack in prison, such as paedophiles.
There is the threat to his family and to Marine A on his release under licence from his life sentence.
It is a known risk. The MoD has taken steps in the past to protect the families of the Marines. There is nothing to suggest that they would not in the future.
Balancing those considerations, we have no doubt that the balance comes very firmly down on the side of open justice; the identity of Marine A must be made public
One in three people believes that a Royal Marine sentenced to life in prison for executing a Taliban fighter should serve no jail time, a poll has found.
A total of 35% of respondents wanted Sgt Alexander Blackman to serve no prison sentence, 23% believed he should do five years, 20% were in favour of 10 years, while 22% thought he should be imprisoned for more than 10 years, the Mail on Sunday reported.
The online poll of 900 people conducted by Survation found that, asked a more general question, 39% of voters said they disagreed with Blackman's 10-year minimum life sentence, while 37% were in favour.
A Plymouth based marine convicted of murdering an injured Afghan insurgent is tonight beginning a life sentence for murder. Sergeant Alexander Blackman who served with 42 Commando will serve a minimum of ten years. He was sentenced at a Military Court in Wiltshire this afternoon.
Blackman, who lives in Taunton, killed the man two years ago.
A Royal Marine said he is "devastated" at being handed a life sentence for murdering an injured Afghan insurgent.
Sergeant Alexander Blackman said he was "very sorry" for his actions, which were filmed on the headcam of a comrade during the patrol in "the most dangerous square mile in Afghanistan".
Speaking after Blackman was led away to begin his sentence in a civilian prison, his solicitor Issy Hogg thanked the public for the support they have shown to him and his wife.
"He has been dismissed with disgrace from the Royal Marines, with whom he has served proudly for 15 years," said, adding that Blackman intends to appeal.