Events have been held across Northern Ireland to mark the end of fighting in World War One.
The conflict ceased on the 11th hour, of the 11th day, of the 11th month of 1918 after an armistice was signed in France.
Remembrance ceremonies were held across Northern Ireland on Sunday morning.
A centenary Armistice Day service took place at St Anne's Cathedral in Belfast, one of four events televised live by the BBC.
The Duke of York arrived at 16:00 GMT to attend the service and gave a reading during the ceremony.
Northern Ireland Secretary Karen Bradley and Democratic Unionist MP Jeffrey Donaldson were also among guests at the service, where poet Michael Longley read his work Ceasefire.
The service in Belfast took place at the same time as services in Dublin, Glasgow and Cardiff and ahead of a service at Westminster Abbey on Sunday evening.
In London, 10,000 people marched past the Cenotaph to honour the fallen, while in France, 70 world leaders, including Taoiseach (Irish prime minister) Leo Varadkar, gathered for an remembrance event in Paris.
In Northern Ireland, the day's events started at dawn with pipers across the UK, including Enniskillen, playing the Scottish lament "Battle's O'er".
Northern Ireland's main remembrance ceremony was held at the cenotaph at Belfast City Hall.
Ceremonies have also been held in Londonderry, Enniskillen, Lisburn and many other towns and cities across Northern Ireland.
In Belfast, wreaths were laid by the NI secretary of state and Irish Tánaiste and Foreign Minister Simon Coveney.
After nightfall, a beacon was lit at a public event in the City Hall grounds.
The Royal Naval Association held its annual remembrance service parade on Great Victoria Street at 10.30.
DUP leader Arlene Foster was among those in Enniskillen, County Fermanagh, for the town's remembrance ceremony.
She told BBC News NI that the event "brought home what a sacrifice was made at that time".
"It is right to remember because when you remember you honour those people who have given their lives for our freedom," she said.
In Derry, wreaths were laid at the war memorial in the Diamond following a two-minute silence.
SDLP Mayor of Derry John Boyle, whose grandfather fought with the 36th Ulster Division, was among those who laid a wreath.
He said that, while he was a nationalist, he did not think his politics or the "politics of any particular party should come into commemorating the loss of Irish, British and European lives".
In Dublin, Irish President Michael D Higgins led a state commemoration of the Armistice in Glasnevin Cemetery.
In a speech, he said that "peace will only ever be established and can only ever be sustained when it is based upon the principals of justice, dignity and mutual respect".
"Let us then, on this day, rededicate ourselves to the cause of peace and the support of those institutions that promotes and preserves the peace," he added.
His official inauguration ceremony took place later on Sunday.
The Royal British Legion held an event at the War Memorial Gardens at Islandbridge in Dublin, which was followed by a service at St Patrick's Cathedral.
The Armistice 100 years on
Long read: The forgotten female soldier on the forgotten frontline
Video: War footage brought alive in colour
Living history: Armistice message to Ulster Division found a century on
On Sunday evening, beacons were also lit in Derry's Guildhall Square, the Diamond in Castlederg and St Macartin's Cathedral in Enniskillen.
Enniskillen also hosted the Piper's Tribute, which saw 100 members of Fermanagh's massed pipes and drums assemble in Church Street.
Northern Ireland's beaches have also been involved in Pages of the Sea, an event devised by film director Danny Boyle.
It was staged at Murlough Beach, Portstewart Strand, Downhill Beach and Port Bán, in County Donegal.
Thousands of people gathered on more than 30 beaches across the UK and Ireland to pay tribute through the medium of art, music and poetry to those who lost their lives in the war.
BBC News NI's Armistice Day coverage will continue across TV and radio on Sunday afternoon with live coverage of the Armistice centenary commemorative service from St Anne's Cathedral in Belfast. Join William Crawley at 15:30 on BBC Radio Ulster and BBC Radio Foyle, and Tara Mills and Seamus McKee from 15:45 on BBC One Northern Ireland.