NI 100: Historians declare 3 May as Northern Ireland birthdate
A panel of historians set up to advise the government on Northern Ireland's centenary has settled on 3 May 1921 as the birthdate of the state.
The exact age of Northern Ireland has divided opinion.
Consideration has been given to at least seven other dates, including the day of the first election and the first meeting of the new Belfast parliament.
But 3 May 1921 was the day the legislation which devised the new political structures came into force.
The 1920 Government of Ireland Act drew a border on the island for the first time and although it took time to take shape it drew up two separate political entities.
An eight-member Centenary Historical Advisory Panel was appointed by Prime Minister Boris Johnson in August.
'Different interpretations'
One of the panel members is historian Dr Marie Coleman from Queen's University in Belfast.
She explained why 3 May 1921 is the date which should be regarded as the beginning of Northern Ireland.
"That's the date on which the legislation comes into effect," she said.
"The following day the lord lieutenant moves the writs for the holding of elections for the parliament of Northern Ireland and the parliament of Southern Ireland."
The Northern Ireland Assembly has also identified the same date.
Its spokesperson said: "While there are different interpretations of this issue and a number of important centenary dates this year, the general historical perspective considers 3 May - the date of the commencement of the Government of Ireland Act 1920 - as the centenary of the creation of Northern Ireland/partition."
The BBC News NI website has a dedicated section marking the 100th anniversary of the creation of Northern Ireland and partition of the island.
There are special reports on the major figures of the time and the events that shaped modern Ireland available at bbc.co.uk/ni100.
Year '21: You can also explore how Northern Ireland was created a hundred years ago in the company of Tara Mills and Declan Harvey.
Listen to the latest Year '21 podcast on BBC Sounds or catch-up on previous episodes.
It has been argued by some that Northern Ireland's status was not confirmed until the dispute over the south of Ireland was resolved.
Dates suggested as the beginning of Northern Ireland include:
- 23 December 1920 - Government of Ireland Act was given royal assent
- 3 May 1921 - Government of Ireland Act came into force
- 24 May 1921 - polling day in the first Northern Ireland election
- 7 June 1921 - first meeting of the Northern Ireland Parliament and appointment of James Craig as prime minister
- 22 June 1921 - state opening of the Northern Ireland Parliament by King George V
- 6 December 1921 - signing of Anglo-Irish Treaty which set up the Irish Free State
- 7 December1922 - Northern Ireland officially opted out of the Free State
- 3 December 1925 - After a Boundary Commission review, it was agreed to confirm the existing border
The Covid-19 pandemic has disrupted plans by pro-union organisations to celebrate the foundation of Northern Ireland.
Both the Ulster Unionist Party (UUP) and the Democratic Unionist Party (DUP) regard 3 May 1921 as the key date.
The DUP said: "Northern Ireland was created as a separate legal entity on 3 May 1921.
"There were a series of subsequent major events as Northern Ireland developed and established itself, for example the opening of parliament."
The Orange Order will also be marking the centenary.
It said: "We recognise that there are a number of key dates... including 3 May 1921 - Government of Ireland Act implemented; 7 June 1921 - Craig sworn in as PM; 22 June 1921 first Northern Ireland Parliament instituted."
The Northern Ireland Office is organising a series of centenary events.
A special postmark and a centenary rose have been created and the programme of events includes an investment conference, a church service, a concert.
The BBC and Queen's University have linked up to mark the centenary of Northern Ireland and partition with a series of authored talks by experts.
The talks, which are available here, are also in podcast format on BBC Sounds.