Perhaps the most evocative of all Scottish monuments is the Scottish National War Memorial within Edinburgh Castle which commemorates the many thousands of Scots from home and from the overseas diaspora who fell in the Great War.

It rapidly became a popular site of pilgrimage for the bereaved after it was formally opened in 1927.

The Rolls of the Dead and the Christian imagery and historical symbols of Scottishness within it powerfully convey the sense of a nation in profound mourning for its lost sons. War is neither glorified nor condemned here. The memorial is simply a witness in stone, brass and glass to each of the services and regiments, combatants and non-combatants alike.

Crowds of excited and chattering schoolchildren both from Scotland and abroad who regularly tour the castle are silenced in awe as they enter the memorial, such is the atmosphere of sadness and contemplation within, which retains the power to touch the visitor a century after the war to supposedly end all wars.

But the sense of loss went much deeper and much wider in Scottish society than the building of a monument in Edinburgh. It permeated all regions and localities. Today there is hardly a hamlet or village in the country which does not have its memorial to the local boys who died fighting for King and Country in far off lands between 1914 and 1918. No other event ever in the national history has attracted so many memorials. Currently, there are 1545 of them, each in their different ways providing a permanent remembrance of the fallen.

And then there are the unremembered for whom there are no memorials: the widows whose lives were tragically shortened by grief and then the burden of bringing up families without a husband and father in sometimes dire post-war economic circumstances; and the mothers, fathers, brothers, sisters, sons and daughters who lost beloved members of their families in a war which claimed more dead per head of the Scottish population than any other conflict before or since.

The most invisible to history, though not to the people of Scotland at the time who would encounter them on a daily basis, were the maimed veterans, the sometimes hideously disfigured ex-soldiers and, not least, the psychologically distressed who continued to suffer as contemporary society struggled to understand and sympathise with their wretched condition.

The outpouring of mass mourning after 1918 was inevitable. After all, this was a country which had not experienced a major European war since 1815. Most fighting had taken place since then in distant and exotic lands at the periphery of empire.

Only the Crimean and Boer wars had presented real military challenges but even they had been fought by professional soldiers with precious little impact on the homeland. The Great War was a radically new experience, not simply because of the enormity of the casualties, but as a result of the huge levels of soldier volunteering in 1914, followed by national conscription. By 1916 there would have been few Scottish families ­without at least one member who had been recruited into the forces.

Computing the actual number of Scottish dead is not easy. Estimates have varied over time. Nowadays more than 100,000 casualties is the most commonly cited figure. Of the 557,000 who enlisted in all services, more than 26 per cent were killed in action on the high seas or more commonly on the battlefields of France, Flanders, Gallipoli, the Middle East and elsewhere on land.

This contrasts with the average death rate in the British Army of 12 per cent of the total. The United Kingdom as a whole lost many young men from the unprecedented carnage of industrialised war but Scotland suffered more grievously than most other areas. The impact of the slaughter in such battles as Loos, the Somme and Arras was rendered more devastating by the modes of recruitment to the colours which often concentrated both volunteers and conscripts from the same localities, districts and even occupations in the specific units.

Hence, during and after major engagements, the death columns of local newspapers were crammed with the names of the fallen and of those missing in action.

Two explanations can be offered for the inordinate Scottish losses. First, during the period before conscription in 1916, Scotland contributed proportionately many more men to the new armies than the rest of the United Kingdom, and the really dreadful losses at the front were sustained in the first few years of war. In 1914 there was a huge response to the call to arms. So great was it in parts of Scotland that recruitment had to be suspended for a time as the recruitment stations became unable to cope.

An extraordinary competition developed between cities and towns as they vied to raise the largest number of recruits. Driving this was the age-old ethos of Scottish militarism. Before 1914 the nation had the highest number of volunteer regiments and part-time soldiers per head of population than anywhere else in Britain. Nearly three out of ten men aged between 18 and 45 were involved to some extent. In addition, when war broke out, large-scale transatlantic emigration from Scotland, which had previously numbered many thousands, all but ceased .

Soldiering became an alternative for a time, not least because it was almost universally accepted that the war would be over before Christmas; being in uniform offered a steady and secure income in uncertain economic times. The rhetoric of the recruitment campaigns was focused on the historic image of the Scot as a warrior.

Posters, press comments and political speeches were all carefully crafted to appeal to a generation of young men bred on a diet of militarism. The Boys' Brigade, whose influence was so widespread among Protestant youth, was organised in quasi-military style and successfully inculcated in its vast membership the soldierly qualities of duty, honour, loyalty, obedience and love of country. Stories of derring-do at the exotic frontiers of empire, school history books and the cigarette cards which youngsters collected also presented battle as an exciting adventure, a wonderful opportunity to rise above the boring and mundane and engage in heroic deeds.

Second, the fame of the Scottish regiments as crack units, distinctively clad in plaid and kilt and the spearheads of the Empire since the eighteenth century, ensured that they were often used as assault or shock troops in the early phases of the great engagements.

Not surprisingly, the losses inflicted were severe. Some Scottish regiments were said to have had an almost suicidal tenacity.

Adolf Hitler, attached to a Bavarian battalion, in Flanders, recalled in Mein Kampf his first experience of confronting them in battle : "After a few days of fighting the consciousness dawned on our soldiers that those Scotsmen were not at all like the ones we had seen described and caricatured in the comic papers and mentioned in the communiques."

Were the unimaginable horrors and terrible losses of the Great War worth it in the long run? The answer to that very big question must be ambiguous at the very least.

The British war aim of defeating Germany and ensuring that no single great power would establish hegemony in continental Europe was achieved. For a time German militarism was crushed.

Nevertheless, the nature of the peace settlement bred intense resentment in the defeated enemy and helped contribute to the rise of Nazism, and eventually to yet another world war.

The costs of the war also bled Britain virtually dry and so led to austere economic policies that helped fuel the industrial recessions of the 1920s and early 1930s.

Those Scottish soldiers who survived returned to a familiar world of poor housing, scant social provision and unemployment that reached epidemic proportions during the Great Depression. The country was certainly not a home fit for heroes.

There is also the impact of the conflict on the development of the Scottish economy in the long run to be considered. Between 1914 and 1918 Scottish industry produced a vast military arsenal.

Unrestricted submarine warfare soon destroyed around one third of the pre-war merchant fleet and so created prodigious new demands for the shipbuilding yards of the Clyde. New orders were immediately placed by the Royal Navy for battleships, cruisers and destroyers in large numbers.

Shipbuilding was the powerful locomotive driving the whole of the Scottish heavy industrial economy and its dynamism expanded the demand for iron and steel. Engineering production was diverted to the mass production of artillery and shells.

Eventually one quarter of a million Scots - including thousands of women - would work in war-related industry in the Clyde valley. Elsewhere, the linen and woollen manufacturing districts of the east and the Borders supplied enormous amounts of tenting and uniforms to the troops.

Trench warfare, which created the enduring image of the Great War, led to unprecedented demand for jute sandbags made in Dundee. By 1918 one ­thousand million sandbags had been shipped to the battlefronts in Europe.

But all this short-term prosperity served to exacerbate the emerging Scottish problem of over-dependency on a relatively narrow range of industrial activities, many of them interconnected and geared to volatile and increasingly competitive international markets.

The war did not create this vulnerability, for which the nation was to pay dearly in the early 1930s, but did intensify it in the long-term. Once again, the results of the Great War for the nation as a whole were ambiguous in the extreme.

Professor Sir Tom Devine has the Personal Senior Research Chair of History at the University of Edinburgh.