A former Royal Marine from County Antrim who made bombs for dissident republicans has been sentenced to 18 years in prison.
Ciarán Maxwell, from Larne, admitted a series of terror charges ahead of a pre-sentence hearing that began last Wednesday.
After his arrest last year, police found 43 weapons hides.
On Monday, an Old Bailey judge told Maxwell he must serve a further five years on licence after his release.
The judge said Maxwell was motivated by hostility to the United Kingdom and had betrayed his position in the armed forces.
He told the former lance corporal that the purpose of a pipe bomb - 14 of which were constructed by Maxwell - was "to maim and kill a potential victim".
The judge rejected Maxwell's account that he was motivated by post traumatic stress disorder resulting from a sectarian beating he received as a teenager.
He said Maxwell was "dangerous" and threatened the political stability of Northern Ireland.
The judge added that Maxwell had "considerable skills as a terrorist bomb maker" and enjoyed his work.
"There was considerable planning, including attack planning, research, and the acquiring of large amounts of materials, including police items for use in disguise," Mr Justice Nigel Sweeney said.
"You were strongly committed to the cause.
"To state the obvious, a skilled bomb maker is of considerable importance to a terrorist organisation like the Continuity IRA."
On Friday, the court heard that Maxwell faked his support for the dissident republicans' cause as he was "frozen" with fear, and that he believes old connections now wish him and his family serious ill.
The 31-year-old was arrested last year after two dissident republican arms dumps were found near Larne.
Maxwell grew up as a Catholic in the County Antrim town and later moved to England, having enlisted in the Royal Marines in 2010.
He lived in Exminster in Devon, and was based with 40 Commando in Taunton, Somerset. He never served in Northern Ireland.
The court was told that four of the pipe bombs he made were used in attacks in Northern Ireland.
Other weapons found in the hides included anti-personnel mines, mortars, ammunition and bomb-making materials.
The former Marine was not in court, but appeared by video link from Woodhill Prison in Milton Keynes.
The judge said Maxwell had enough chemicals in Northern Ireland to create "100 kg of high explosives, larger than the notorious Enniskillen bomb."
It was heard that when Maxwell applied to the Royal Marines in 2009, he said he had "no beliefs" on an application form.
The judge said there was "insufficient evidence" to suggest a sinister motivation for joining the Marines.
Police Service of Northern Ireland Ass Ch Const Stephen Martin said: "Ciaran Maxwell is an extremely dangerous individual who was capable of gathering a large amount of munitions over multiple sites in Northern Ireland and England.
"The hides uncovered at Larne and surrounding areas collectively, amount to one of the most significant seizures of munitions in recent years in Northern Ireland, not to mention the further items recovered in hides in Great Britain.
"It is obvious that these materials and munitions were sourced, gathered and constructed over significant periods of time which demonstrates Ciaran Maxwell's determination and committed planning.
"These items are designed to cause damage, serious injury and to kill."
Secretary of State for Northern Ireland James Brokenshire said: "I pay tribute to the police and other agencies in successfully bringing this case before the courts.
"This has undoubtedly saved lives."
Maxwell was also convicted of possession of cannabis with intent to supply and had images of other people's bank cards and identity documents which he intended to use in online fraud.