IT happened all over Scotland. In Glasgow, the crowd was so big it overflowed from George Square into the adjoining streets. Many people hung out of windows to get a good view; some even climbed on to the roofs. It was another sign, said the Glasgow Herald, of the regard in which the great man was held.

It was the same in Dundee. There, the welcome was so affectionate it seemed to make up for everything the old general had been through in the war. “The crowds were quite extraordinary,” he said – so extraordinary that he fancied even the city’s MP Winston Churchill would have been impressed by it all.

And it did not end there. St Andrews University elected him rector. Edinburgh gave him an honorary degree. He was awarded medals and honours by nations around the world. A football team in Argentina was named after him (and 100 years later Club Atlético Douglas Haig still exists). As for the man himself, he simply said: “What a business it all is.”

And then, if there was any doubt left, the general’s death in 1928 confirmed the greatness of his life. In London, crowds lined the streets as his coffin was taken to Westminster Abbey. Later, it was sent north where another huge crowd waited in Edinburgh. The Secretary of State for Scotland said the country had lost a great Scotsman and a great leader. Edinburgh’s Lord Provost said Scotsmen especially were proud that their comrade had risen to the occasion when the country’s call came.

So who on earth can we be talking about? Not Earl Haig surely? Not the donkey who led the lions, not the man so often portrayed as a moustachioed nitwit, a military nincompoop; not the man painted as the heartless general in a chateau who thought the First World War could be won with cavalry charges and sent men to their deaths to gain a few inches of sodden, useless land? Is that the man who was feted in Scotland; is that who the crowds turned out to see?

Surprisingly, the answer’s yes and it’s an extraordinary contrast: Earl Haig as the country saw him in the years after the war and Earl Haig as he is seen now after decades in which his reputation has been taken apart by his critics. It was a process that began with the poems of Wilfred Owen, Siegfried Sassoon’s Memoirs of an Infantry Officer and RC Sherriff’s play Journey’s End. It continued in the 1960s with The Donkeys by the MP Alan Clark and Oh! What a Lovely War and in the 1980s with Blackadder Goes Forth. The BBC comedy famously showed Haig sweeping up model soldiers with a dustpan and brush and chucking them over his shoulder. The aim of every military effort on the Western Front, said Rowan Atkinson as Blackadder, was to move Haig’s drinks cabinet six inches closer to Berlin.

But how true is this picture? Ahead of the centenary of the beginning of the Battle of the Somme on July 1, Haig is still a controversial figure and the battle’s 419, 654 British casualties help explain why. But there have also been efforts by some historians to look again at his reputation and ask whether the commander of the British Expeditionary Force deserves all the opprobrium and hate.

One of the historians who believes he does not is Gary Sheffield, professor of war studies at the University of Wolverhampton and the author of a number of books on the First World War. His latest is a new and updated version of Douglas Haig: From the Somme to Victory which has used previously unknown private documents to challenge some of the accepted beliefs about Haig.

Sheffield says he wanted to write the book because, for a historian of the First World War, Haig is the ultimate challenge. Having edited the commander’s letters and diaries 10 years ago, Sheffield says he came to realise there was a lot more to Haig than he thought there was and that the real commander-in-chief was very different from the incompetent buffoon of caricature.

The problem, says Sheffield, is that Haig has come to symbolise everything that was wrong and wasteful about a bloody war. “As the man at the top he does bear some responsibility,” Sheffield says. “But he has almost been made to bear all the responsibility. So for example people say things like: ‘Why did he send men to fight in the Western Front?’ Well, of course he didn’t – he was just the commander in the field, he did not run the entire British army.”

Sheffield also believes Haig has been unfairly judged for being a man of his time. He was born in Edinburgh in 1861 into a life of privilege although he did not have the easiest of childhoods, as he suffered terribly from asthma and his father was an alcoholic. “He is very much a late 19th-century figure,” says Sheffield. “He’s not a 21st-century man and is unsympathetic to people today. People don’t have any problems looking at Henry VIII and putting him in his context – he was a man of a different time – but because there are still people alive today who were small children when Haig was commander in the field, he seems like our contemporary but of course he isn’t – he’s a historical figure. So there is a sense that he is being blamed for not being like us.”

As a person, Haig could also be hard to like. He didn’t do small talk, his manner could be abrasive and he was no master of the one-liner like Churchill or a great populist like Field Marshal Montgomery. But once they got to know him, Haig’s staff were devoted, and after the war, Haig was also greatly popular with ex-servicemen as head of the British Legion. Considering that veterans are still coming out of the armed forces 100 years later without proper care and support, Haig’s role as a passionate spokesman for veterans reflects well on him. And, of course, the Poppy Appeal is still going, thanks largely to Haig’s early efforts.

In fact, so popular did Haig become with veterans that it aroused some suspicion in the establishment; there were even fears Earl Haig could become the British Mussolini and lead a popular revolution. “It was never going to happen using Haig,” says Sheffield, “because he was a conservative figure, and he was never tempted to go down the extra-constitutional route.” But unlikely as it may seem now, a British revolution was a possibility in the 1920s – and it may have been only Haig’s personal conservatism that stopped it.

So what of Haig’s role in the war itself? The popular image of him is that he was wedded to the idea of throwing soldiers against barbed wire rather than seeking a technological solution, but that does not square with the performance of the British Army which did adapt to the new conditions. Some have argued that these improvements happened in spite of Haig but Sheffield says that simply will not do: Haig deserves a sizeable share of the credit for the way in which the army changed.

“Tactics by the end of the war were basically based round the light machine gun and the tank, and they changed very dramatically and Haig is the man who oversees that transformation,” says Sheffield. “As for strategy, you can certainly criticise it – you can say that he prolonged battles beyond the point at which they were useful but even there you have to bear in mind that he is never a free agent – he’s playing second fiddle to the French and the French always want the British to fight on.

“But ultimately, there wasn’t much that Haig could do – the imperative was to attack, to drive the Germans off French and Belgian soil. You could argue that he could have gone about that in different ways – he certainly could have improved his methods at various times – but ultimately there was only so much you could do and as long as the politicians were incapable of settling their differences at the political level and having a diplomatic settlement that’s what the armies had to do.”

Sheffield also rejects another of the popular images of Haig as a man who refused to recognise that the days of cavalry were over. Famously, Haig said he believed the horse would always be important on the battlefield. “Aeroplanes and tanks are only accessories to the men and the horse,” he said, “and I feel sure that as time goes on you will find just as much use for the horse – the well-bred horse – as you have ever done in the past.”

That may look hopelessly antediluvian, but Sheffield says we should not judge Haig too harshly for that remark and says the general’s views on horses were mainstream for the time. “The idea that horses are completely obsolete on the Western Front isn’t true and when Haig made his notorious comment about the importance of the well-bred horse, he was talking about horse breeding as a science which is important and horses are important for getting guns from A to B and all the rest of it. The real problem is that the batteries for his crystal ball had run down and he couldn’t see 20 years in the future. Everybody in the mid-1920s thought the horse would still have a place on the European battlefield 20 years hence. It turns out he’s a poor prophet.”

As for Haig’s bigger strategy for the war effort, Sheffield believes it was the only one that was possible: to take the offensive and to constantly push for victory. Every sinew had to be strained to defeat the Germans and eventually it was hoped a strategy of attrition would win through, which in the end, of course, it did. Haig’s analysis in his final despatch of 1919 was that the enemy had been worn down to the point where the Allies were able to deliver the coup de grace during the Hundred Days of August-November 1918. Sheffield’s contention is that Haig was right.

Sheffield does acknowledge Haig’s faults– he was frequently too optimistic and gave too much credence to political intelligence about the German Army – but he is fierce in his defence of the man against the myths: that he was technophobe or stupid. He also denies being an apologist for Haig.

“It’s simply not true. I’m a professional historian and have spent 35 years working in the archives. What I’ve come up with is not perfect but it’s a nuanced view based on my study of the archives. I approached it from the point of view that Haig is a thinking, intelligent soldier, not brain of Britain or anything, but nevertheless he is not stupid and once you start looking at it in that light, you find all sorts of things which appear to be inexplicable, suddenly drop into place.”

However, Sheffield does still fear that, in trying to change the popular view of Haig, he might be fighting a losing battle and that the more nuanced view will be lost amid all the usual cliches.

“I must say that the next couple of months with the centenary of the Somme I expect we will have all the old cliches dragged out,” he says, “and that’s going to be difficult for those of us who want to have a more balanced view of the First World War.”

But he saves his last thought for Blackadder, which has played such a big part in spreading the myths about Haig and how the war was fought. “Blackadder is wonderfully funny and says a lot of wise things about war and our perceptions of the war,” says Sheffield, “but it isn’t a documentary.”

Douglas Haig: From the Somme to Victory by Gary Sheffield is published by Aurum at £25.