The earliest known portrait of Robert the Bruce, shown on these pages, was painted for the entrance of Charles I to Edinburgh, in 1633 for his coronation.

It formed part of a triumphal arch carrying portraits of various Scottish kings, real and imaginary. When the arch was demolished it was removed to Newbattle Abbey until the 1970s, when its current owner bought it at auction.

Though not a portrait in the real sense, since the subject had been dead for more than 300 years by the time it was painted, it nevertheless captures some of the qualities of Scotland's most revered and often idealised historical figure: a fearless warrior who was a little rough around the edges, but also an aristocratic gentleman, and a thoughtful one at that.

As the 700th anniversary of Bannockburn gallops towards us, like a war horse on the charge, there has been a spate of new books to mark the occasion. Since almost all acknowledge their debt to the late Professor Geoffrey Barrow, whose magnificent Robert Bruce, first published in 1965, remains the standard text on the subject, one wonders if there was really any need for these retellings of a tale so often told, especially since Edinburgh University Press last year reissued the Barrow. That question is quickly answered on reading the following books, some of which are useful additions to the Bruce shelf, and one an outstanding piece of history that deserves to stand comparison with Barrow.

In a bid to do something fresh for younger readers, and those - like most of us - who need to be reminded of the outline of the facts, James Robertson's Robert The Bruce King Of Scots is a clever distillation of the key facts. Robertson cuts with ease through the complexity of the political manoeuvring that led to Bannockburn, boiling the story to its bones. We see Wallace's execution, and Bruce's exile and return, his murder of John Comyn, and the inglorious fighting between Scottish nobles as they took sides with Bruce or John Baliol, who had been named King of Scotland under Edward I's punishing thumb. And then we reach the battle itself.

Robertson's writing is deceptively simple and beautifully clear, but what makes this book so special is its extraordinary illustrations. Jill Calder's images are stunning, capturing the murkiness of 14th-century Scotland with a boldness, vigour and moodiness that manage to be both intensely modern and evocatively medieval.

Alistair Moffat's Bannockburn is a pacy account of the days leading up to the battle. It may add nothing to the history of the period, but he is a natural raconteur, and particularly good at including the sort of memorable detail that is often ignored. One such is the story of Edward II's favourite, Hugh Despenser, who had taken the place of the king's exiled lover, the much loathed Piers Gaveston.

Despenser was so sure of English success that he set off north accompanied by baggage wagons bringing furniture to furnish his new homes in the earldom of Moray the king had promised him. Of Edward's headlong escape from Dunbar after the battle, Moffat comments only: "Hugh Despenser was also on board, without his furniture."

As all writers on these events are aware, one of the most important acts after the battle came in 1320, with the Declaration of Arbroath, which reiterated Scotland's independence. Of this key document, Angus Konstam writes, in Bannockburn, "it ... contained a clear message about national identity. Scotland was more than just a land or a kingdom - it was a sovereign nation, with the strength to repel invaders and the skill to govern itself."

Konstam's revisiting of the period is a rattling journalistic overview of the key events, told in a spirited, somewhat bombastic tone, with strong political overtones. It is clearly his hope that after reading his version, those voting in the referendum will have a better idea of what Bannockburn means and how it will influence their decision.

In his final chapter, Konstam reflects on the battle: "To steal the words of Sir Winston Churchill when he made a speech celebrating the victory of El Alamein in 1942: now, this is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning."

It is to Michael Penman that we must turn fully to understand the role Bannockburn played in shaping Scotland. A Senior Lecturer in History at Stirling University, Penman's Robert The Bruce: King Of The Scots might equally, he writes, have been called After Bannockburn. Although it gives a good account of Bruce's life prior to the battle, more of the book is devoted to what happened next. Even as late as 1323 Bruce was peevishly complaining that in correspondence with Edward II and others "there is no more reference made to us [as king] than to the meanest of our realm". Bannockburn, sadly, did not change things overnight.

Penman's book is first-class history: detailed, closely argued and ringing with the authority of one steeped in the period. Though it requires concentration, it amply rewards it. What becomes very clear is that while there is an enjoyable, jingoistic chutzpah to many popular versions of the story, Bruce in such accounts is little more than a nationalistic cipher. The real man cannot emerge except through the careful accumulation of hard facts. Those wishing to meet him should therefore start with this book. Under Penman's scrupulous hand, Bruce emerges as ambitious, flawed, generous and deeply devout.

Of his religiosity, Penman writes: "Robert's evolving and genuine, carefully considered piety remains the most neglected strand of his kingship and its innovative search for legitimacy." The Scottish church was to play a large part in that, even as the Pope's excommunication of Robert for his murder of John Comyn hung over him for many years.

Treating the chroniclers of the times with caution - especially Barbour and his exaggerations and revisions - Penman has painstakingly trawled original sources to piece together the run-up to the battle and the way Bruce gradually pulled his supporters together in its aftermath. Of the ultimatum given by Edward Bruce to the keeper of the English garrison at Stirling Castle, which took place a mere month before the June solstice of 1314 (not a year earlier as myth has it), he comments: "Crucially, the Bruce brothers had now determined the time and stage of engagement if a battle was to be fought." Bruce had not, therefore, been bumped into a fight he had never wanted, but seems to have carefully orchestrated it.

The immediate wake of the victory at midsummer has always been recognised as a politically precarious time for Bruce, but it is rather startling to learn that it was the birth ten years later of his twin sons, John and David, that proved the watershed. Not until 1324 was uncertainty about his direct succession finally removed, and political stability after his death assured. That John, probably the elder son, died in infancy was troubling, but David, who would become David II, thankfully thrived.

Sober historian that he is, Penman takes nothing at face value. Of the hard-won 1328 peace treaty with England that some see as the end of the country's troubles, he writes: "What has been underestimated is the level of disquiet that some of the conditions of peace unleashed within the Scottish political community". And well they might, since they saw some of those who had opposed Bruce have their lands and inheritances restored to them.

Penman's scholarship is commendable, his style clear, his contribution to this field a truly original and quietly groundbreaking addition to the known facts of Robert the Bruce. It is essential reading as midsummer draws near - and long after.

Can historical fiction add anything to what we know of Bannockburn? With Robyn Young's meticulously researched Kingdom one suspects this might be more faithful to the records than many a supposedly factual account. The third in her Insurrection trilogy, it opens with the young Robert the Bruce being handed his father's mantle as Earl of Carrick, and assuming the burden of his family's claim to the throne of Scotland. What follows is an impressively undeviating reconstruction of events, Young inventing passages where facts are threadbare, but otherwise keen to remain close to the truth. Indeed, in her endnotes she tells readers what is made up and what is not, lest they are misled.

This is not fiction for the fainthearted. It teems with characters and the intricacies of the feuding, treacherous English court and Scottish nobility. Perpetually in a state of unrest, Kingdom lacks the modulated pace and rhythm of made-up drama. There is so much history to cover, too, that Young has to reign in her descriptive abilities, when more would have been welcome.

Despite this it is compelling, the author's devotion to her subject making the story blaze with passion. By its end, when a magnanimous Robert behaves towards his enemies as only the most chivalrous of kings could, credible personalities have been put to the roll-call of well-known names, and their fates powerfully evoked. As one closes this book - and all the others - it is hard to believe these players have been dust for 700 years or more.