By Kevin Connolly
BBC News Ireland correspondent
On the 90th anniversary of the Easter Rising, the BBC News website considers its significance and the electoral attraction of marking it.
Rebels fought against British rule in Ireland
On Easter Monday in 1916 a motley group of rebels set out through the streets of Dublin to loosen Britain's imperial hold on Ireland by force of arms.
They were soon dislodged from the curious assortment of buildings, including a biscuit factory and the General Post Office, which they seized.
But the grip they took on the political imagination of the nation too shows no sign of slackening.
They almost certainly knew that in military terms, their venture was doomed from the start but in Irish eyes that helped to make the rising a kind of study in miniature of centuries of hopelessly unequal struggle against British rule.
That wasn't of course how Britain saw it.
Two years into the Great War - a war in which tens of thousands of Irishmen, Catholic and Protestant, were fighting under British colours in Europe - the Easter Rising was seen as a treasonable stab in the back.
The standard reading of what happened next is that a combination of stupidity and brutality on the British side helped to ensure that the rebels - who were viewed with some suspicion and hostility in Dublin at first - became national heroes.
Nearly 2,000 were interned and 15 of the leaders were executed.
One of them, James Connolly - a radical Scots-born trades unionist - was so badly injured that he had to be tied to a chair so that he could be shot by firing squad.
He'd gloomily speculated that the rebels would be slaughtered, but not all of his predictions were so accurate; he also believed generals working for a capitalist power wouldn't use artillery to put down the rebellion for fear of damaging private property too.
The scale of destruction in the burning ruins of Dublin showed he had underestimated his enemy.
But you can't judge the past by the standards of the present.
The British Army shot more than 300 of its own soldiers for cowardice and desertion during World War I.
From the generals' viewpoint the rebels could hardly expect better treatment.
And it wasn't just the executions that sealed the rebels' place in Irish history.
One of their leaders, Padraig Pearse, used his brief time in command at the Post Office to read out a "proclamation of the republic" - a ringing declaration that Ireland, long part of the British empire, was now independent.
It was six years before that vision was realised, and a lot more blood was to be shed first. Even then, victory was partial because Ireland was partitioned, with the six north-eastern counties remaining firmly in British hands.
But most Irish people regard the Rising as a defining moment from which the legitimacy of the modern republic flows.
Given all of this, the 90th anniversary was always going to be seen as something to celebrate - not least because almost all of the main parties in the Irish republic trace their origins back directly or indirectly to that little group of rebels.
Documents from the Easter Rising were recently auctioned
The main party in the governing coalition, Bertie Ahern's Fianna Fail, has always styled itself a republican party - but even the staid and rather conservative opposition Fine Gael has been reminding voters of its own, normally well-hidden, rebel credentials.
Their predecessors and great-grandfathers too fought in those burning ruins even though their current leaders are trenchant critics of the modern republican movement.
You can see what's motivating them. There's an election next year and there seems every prospect that Sinn Fein, the political wing of the IRA, will perform even more strongly than it did the last time.
So the anniversary probably seemed to Mr Ahern to be a good time to remind the voters that it's the older parties in the South, rather than the largely northern-accented upstart, which are the true inheritors of the spirit of the Rising.
A parade by the defence forces will underline the message that it's the soldiers of the Irish Army and not the paramilitaries of the IRA, who stand in a direct line of descent from the volunteers who followed Pearse and Connolly.
During the troubles in Northern Ireland it was seen to be impossible to mark the Easter Rising with a military parade.
Most people in Ireland draw a moral and political distinction between the activities of the "old" IRA in the 1920s and those of the Provisional IRA in the 1970s and 1980s but there was a general feeling that a military marchpast might have blurred that distinction.
So it's with a sense of relief that the commemoration is now restored - but when you watch the celebrations, remember that modern electoral subtext. The shots in that 21-gun salute are the first shots in next year's election campaign.