Few countries were more decisively affected by the Great War than Ireland. Irishmen from all backgrounds (210,000 of them) fought in greater numbers than in any other conflict in the country's history, while Ireland's modern political shape to a large extent derives from the war.
The average person today is far more likely to have a relative among the 49,000 Irish dead of the Great War than among those of the War of Independence and Civil War, whose combined death toll was less than one-sixth of that number.
Of course, wars are about more than the body count. But since the Great War split the nationalist movement, confirmed partition and transformed political cultures in both parts of the country, it can scarcely be claimed that it was incidental to the course of national affairs. Independence and partition would have occurred in some form or other anyway. But the war had everything to do with the shape they actually took.
Recent years have witnessed a sea-change in public and official awareness of the Great War. During Queen Elizabeth's state visit in May 2011, the Irish National War Memorial Gardens at Islandbridge shared almost equal symbolic status with the Garden of Remembrance in Parnell Square.
Yet 30 years ago, Islandbridge was a ghostly wreck, overgrown and denied official meaning. A few historians (such as David Fitzpatrick) and journalists (notably Kevin Myers) proclaimed the significance of Ireland's First World War largely to deaf ears. Then the OPW restored Sir Edwin Lutyens' magnificent memorial at Islandbridge, which was formally dedicated in 1988.
In the 1990s, under Tom Burke's quiet inspiration, the Royal Dublin Fusiliers' Association began to draw attention to the depth of ordinary Irish involvement in the war, tapping into a vein of family memories. Other civic memory groups followed.
The peace process in the North gave the single biggest fillip to this process. The Island of Ireland Peace Tower, which was inaugurated in 1998 at Mesen in Belgium, where unionist and nationalist soldiers had fought together in 1917, was its clearest symbol.
But the reality driving it was the way in which, not just in the North but also in the Republic, the end of the Troubles gradually dissolved the more polarised views of history that had prevailed over the previous 30 years. A more complex understanding of the all-island story came into view and especially in relation to the Great War, which had occasioned the bitter divisions within and between the two Irelands.
The rediscovery that more Catholics and nationalists than Ulster unionists had fought in the war provided an obvious theme of reconciliation. But it also meant that when, in 2006, the Republic decided to mark the 90th anniversary of the Somme as well as the Easter Rising, it accommodated not just unionists but also two strands of the nationalist past, republican and Home Rule.
Yet a century on, perceptions of this seminal event in Ireland's history remain oddly blurred. A quick glance in any bookshop shows that titles dealing with the Easter Rising, the War of Independence and the Civil War vastly outnumber those on Ireland's Great War, despite welcome additions to the latter category.
Recent history PhD theses tell the same story. The events of 1919-23 are of abiding importance and they naturally generate new debates. Nonetheless, the disparity between this degree of attention and the relative neglect of World War I is striking.
See our dedicated World War 1 section here.
Moreover, the worthy search for themes of peace and reconciliation cannot eliminate divisions and contradictions that go back to the war itself.
When Queen Elizabeth paid her respects at the Garden of Remembrance to 'all those who died for Irish freedom', did these include the nationalist dead of the Great War? When she placed a wreath at the Islandbridge memorial to all the Irishmen who died in that war, these included northern unionists (their representatives were present on the occasion) who by definition are excluded from the Garden of Remembrance.
Come 2016, it is still not certain that there will be 'parity of esteem' for these jostling histories, however much we might wish (and work) for this to be so. But nor should there be any attempt in the name of official commemoration to gloss over the antagonisms that pulled apart both Ireland and the United Kingdom a century ago.
So how might we look at Ireland's Great War in a way that restores it to something like its true weight in the history of both parts of the country? There seem at least two ways of doing this.
The first is to acknowledge fully the impact the war had on Ireland in myriad ways. The time is well past when it could be seen as an imperialist war foisted on Ireland by an alien Britain. Of course, Ireland could not respond to the war as a sovereign state. That was precisely the drama of Home Rule, which had been thrown into crisis by the Ulster revolt and then suspended by the war.
But across Europe, and especially in the east where dynastic empires still prevailed (Russia, Austria-Hungary, Ottoman Turkey), different nationalities were caught up in the war in a similar way to the Irish, and often without John Redmond's authority. Since Ulster unionists also supported the war, albeit to reject Home Rule, the quarrel over partition was both sidelined yet also supercharged by the sacrifice in the trenches even before the Rising added a radical nationalist alternative.
Politically, one of the main drivers of the Great War turned out to be the creation or consolidation of nation-states as the key form of organisation and identity across Europe. In that perspective, Ireland's story is a particular variant of a general theme.
One of the things that made it particular was the voluntary nature of the Irish military effort. In fact, the volunteer in every sense stood at the heart of the Irish war experience.
Continental European armies had millions of men because they were based on universal short-term conscription, with those who had completed their service being called back in time of war. Britain, as a naval power, had no such tradition, and in the first half of the Great War performed the extraordinary feat of raising a continental-size army by voluntary enlistment.
Ireland was an integral part of that process. It made wartime volunteering very different from enlistment as a professional in the small, peacetime army. A whole cross-section of Irish society joined up (albeit with differences of class and region), making it a national experience, whatever the range of individual motives.
It was this that so exercised the radical nationalists before the 1916 Rising. They feared losing out in the struggle for Irish political allegiance, which (thanks to the war) was now expressed in military terms. It was also this that united nationalist Ireland against the attempt to impose conscription in 1918, two years after its introduction in Britain, because it destroyed the implied political compact of volunteering.
The fact that Ireland's military effort remained voluntary throughout had implications for the country's exposure to battle. While huge in terms of Irish history, it was lower than that of countries with compulsion (only Australia joined Ireland in rejecting conscription). In fact, with roughly the same size population as Ireland, Australia had nearly twice as many volunteers and roughly double the Irish military death rate, which places Irish support for the war in a useful perspective.
Nonetheless, the considerable numbers of Irishmen who fought on the Western Front, in the Balkans or in the Middle East shared the devastating experience of industrialised warfare, with unprecedented deaths, wounds and mental disintegration. And they did so on a scale that ensured few communities back home remained untouched.
In this sense, Irishmen and Irish society were part of the Great War as the formative catastrophe in Europe and the world in the early 20th Century. These are the personal traces of the war that so many people are now beginning to discover in their own family histories. They also mean that the Republic has every right to take its place at the international commemorations of the centenary of the Great War.
The war affected Irish life in other ways that were both similar and different to elsewhere.
Middle- and upper-class women across the country joined their sisters internationally in taking up new roles (such as volunteer nursing) or traditional roles on a new scale (eg, charity work in support of war victims). Belgian refugees came to Ireland seeking shelter and work – a back eddy of the vast displacement of civilians across Europe and the Middle East caused by the war. Working-class 'separation women', source of both jibes and jealousy as they collected the 'separation allowances' that compensated for the absence of their men at the front, had their equivalent in every belligerent society, including Russia.
Yet class relations were disrupted less in Ireland than in many other countries. The vast industrial output required by this grim war of attrition between the world's major economies created a wartime industrial society wracked by growing social unrest and protest.
In Ireland, only the industrialised north-east experienced this to any degree, and there the tensions of class were mitigated by those of religion and ethnicity. In fact, high agricultural prices brought some prosperity to rural society, although this emboldened agricultural labourers to demand better conditions.
Did all this amount to an Irish Home Front (the term in Britain dates from 1917) at least in the first half of the war? If so, did a continued sense of a Home Front in unionist Ulster, while nationalist Ireland turned against the war after the Rising, create a cultural and social partition during the war itself, well before the political fact in 1921-22? Only when new work of the kind that many local history societies and professional historians are now undertaking has brought the war experience firmly into focus will we be able to answer such questions.
A second, quite different way of reassessing the nature of Ireland's Great War draws on the latest international scholarship by suggesting that we think of the Great War as a larger cycle of violence.
In this view, the 'Greater War' began in 1912, when Ulster was armed and a first Balkan war lit the fuse for 1914, and it ended in 1923. For the fighting did not stop in 1918 but metamorphosed into a series of revolutions, counter-revolutions, civil wars and brutal ethnic confrontations. These added several million more to the death toll of the Great War, brought communism and fascism to power in Russia and Italy respectively, and saw the violent birth of new states in eastern Europe – and Ireland.
Ireland's revolution and partition seem less uniquely national if we adopt the perspective of the 'Greater War'. This helps us to understand the ethnic tensions during the War of Independence or the pogroms against Catholics in the North as comparable to the violence between Germans and Poles in Upper Silesia. It enables us to see that guerrilla warfare and counter-insurgency were the hallmarks not just of the War of Independence but also of struggles in the newly independent Baltic states or the bitter struggle between Greeks and Turks in Anatolia.
Violent as our Civil War was, it pales into low-intensity combat alongside the civil war in Finland, also of similar population size to Ireland. There, social class was an issue and 1pc of the population (36,000 people or more than the Irish dead of the Great War) perished in six months in 1918. The shadow of the gunman fell across much of Europe in the Greater War.
Playing with such frameworks of interpretation might seem just that, a kind of intellectual game. Yet nothing could be further from the truth. For the ways in which we look at the past are themselves shaped by history.
The Great War and its legacies partitioned our understandings of our own past, splitting them first between unionist and nationalist and then between opposed versions of republicanism and the vanished perspective of Home Rule nationalism.
Fresh ways of thinking about the impact of the Great War and its relationship to what came afterward are vital to overcoming the partitions in our own collective mind.
And these include the ordinary people – the women, the workers, the soldiers, the children – who all too rarely made it on to the historical agenda at all.
‘Our War – Ireland and the Great War’ by John Horne relays the experience of ordinary Irish people. Irish Independent readers can buy it from the Royal Irish Academy (www.ria.ie - enter the code ‘Independent’) for €25 with free postage in May and June.
‘Towards Commemoration’ by John Horne & Edward Madigan is on sale from www.ria.ie at €15. The book features essays by leading historians, journalists and civic activists debating how to make the most, and avoid the worst, of the centenary decade
See our dedicated World War 1 section here.