If the Irish state visit isn't a triumph, it won't be the fault of the Royal family. Yes, diplomats from the Foreign Office, the Irish department of foreign affairs, Michael D Higgins's own team and even the Northern Ireland Office will have been labouring long and hard over every part of the programme laid on for the Irish president and his wife, Sabina, but the Queen is the hostess and she takes her job seriously.
Notoriously, she takes a close interest in every aspect of such events, right down to checking the table settings for banquets, and this visit matters to her more than most.
In the same way – in partnership with her senior dresser, Liverpool-Irish Angela Kelly – clothes and jewellery for her long-desired visit to Ireland were meticulously and sensitively chosen to strike chords with her hosts.
The Queen's agreement will have been sought on having the visitors headquartered at Windsor Castle, which is a sign of special favour, and for making this an unusually long visit.
Two to three days is the norm, but President Higgins and Sabina will be around from Monday to Friday. Now, admittedly, on Monday, they'll be met at Heathrow by a mere Lord-in-Waiting and whisked off for a night at the Irish embassy, but a full four days of activity are planned before they're due to be seen off at Coventry airport by the Lord Chamberlain, the senior official of the Royal household.
(Incidentally, why has Coventry been chosen for special attention? Is it because it's twinned with Cork, where security was relaxed, the crowd got to meet her and the Queen had the happiest time of her Irish visit?)
The Queen is fully aware of the extent to which her family will add fairy dust and symbolic underpinning to the proceedings and, other than young Prince George, who will be given leave to slumber in his cot, they will be under orders to turn up and play their part. Prince Charles and the Duchess of Cornwall will be at the Irish embassy on Tuesday morning to greet the visitors.
In the long process of preparing nationalist Ireland for a visit from the Queen, Charles made a key contribution, in spite of having suffered much personal grief from republican violence.
(In 1979, aged 30, he was hit hard by the murder of his great-uncle Lord Mountbatten. He would subsequently propose to Mountbatten's granddaughter, Amanda Knatchbull, Charles's on-off girlfriend, but having also lost in the bomb a grandmother and her youngest brother, she decided to stay a social worker rather than become a royal, so he settled for Diana Spencer, instead.)
He willingly tested the water with what was termed an 'official' visit to Ireland in 1995. He was welcomed emotionally by the-then taoiseach, Fine Gael's John Bruton, and, in spite of opposition from republicans and Peter Robinson, the event was a great success.
In 2010, Charles and Camilla were guests of honour at the first visit by a royal to the Irish embassy in London, where those present – including me – cheered when he memorably prefigured his mother's later comment in Ireland that "we should bow to the past, but not be bound by it" with the line that "we should endeavour to become the subject of our history and not its prisoners".
It was underestimated by many – including tunnel-visioned republicans and unionists – how sick were the Irish in Britain of victimhood, narrowness, bigotry and the picking over old sores; how integrated we are and how desperately we crave a normal relationship between the two countries we love.
There was – as, to its discomfiture, Sinn Fein found out from the Queen's 2012 visit – a similar mood in Ireland.
Charles and Camilla will escort the Higginses by car to Windsor, where they will be welcomed by the Queen and Prince Philip at a meeting place known as the Royal Dais and taken in a horse-drawn carriage to the castle for the inspection of the Guard of Honour, the playing of both national anthems, and, after lunch, a look at Irish-related items from the Royal Collection – after which the president goes to London to visit Westminster Abbey and lay a wreath on the Grave of the Unknown Warrior.
The president will then address both houses of parliament, attend a reception with the all-party parliamentary group, return to Windsor and meet earnest Ed Miliband, leader of the Opposition. As if all this were not gruelling enough, he will then attend the state banquet and make a speech.
The state banquet will undoubtedly be stuffed with royals and the Irish will be looking out for photographs of the president with Wills and Kate. The couple have already developed Irish connections and will be seeking to expand on them.
Prince William, who has been a member of both the Army and the RAF, married in 2011 in the uniform of the Irish Guards, a regiment of which he had just become honorary commander. His wife took over from Princess Anne, who took over from the Queen Mother as the royal who dishes out shamrock to that regiment on St Patrick's Day – and very fetching she looked in dashing green, sporting the shamrock brooch that annually is lent for the ceremony by the regiment.
On Wednesday morning, Prince Andrew will show up to take the guests to the grand stairs in Windsor Castle to view the Colours of Irish regiments disbanded in 1922.
(Although this is not on the same ground-breaking level as the Queen bowing to the Irish dead at the Garden of Remembrance, it's yet another powerfully symbolic moment to which, no doubt, President Higgins will respond with appropriate respect.)
Andrew was a helicopter pilot during the Falklands war, but he will undoubtedly keep his lip zipped about the appalling behaviour of taoiseach Charles Haughey at the time and the ill-informed Irish enthusiasm for the brutal Argentinian junta. But, having spent years serving as a global trade ambassador for his country, he will have much else to discuss with the guests. So, too, will the Queen's cousin, Prince Richard, Duke of Gloucester, an architect with a passion for conservation issues, heritage and historic monuments. He and his Danish wife will represent the Queen at the banquet given for the president by the Lord Mayor of the City of London on Wednesday and at the Ceiliuradh (celebration) concert the next night at the Royal Albert Hall.
I've been asked to that and though I doubt if it's my kind of music, I'll be cheering, for this is a wonderful few days for Anglo-Irish relations and it behoves those of us who are not malcontents and curmudgeons to rejoice.
Relations between the establishments, as well as the rank-and-file of the two countries, are now mostly conducted with mutual respect and affection. The British have long got over the notion that it is their mission to tame a wild people and the Irish have outgrown their inferiority complex.
So, where is Northern Ireland in all this? Well, it behoves unionists to remember that President Higgins is visiting their state and their Queen and deserves a proper welcome. Nationalists, too, might remember that letting go of grievances should be a two-way street. They might bear in mind, too, that the Royal family abhors sectarianism, with Prince Charles a student of all world religions and a frequent attender of services in mosques and synagogues and temples.
"He makes all British citizens feel they are part of the grand historical narrative," says Farhan Nizami, director of the Oxford Centre of Islamic Studies, of which Charles is patron. He has made it known that, as King, he would wish to be known as "Defender of Faiths", rather than "Defender of Faith", a royal title since the pope conferred it on Henry VIII in 1521 not long before he split with Rome.
As head of the Church of England, the Queen is more cautious, but she was delighted in 2012 in Enniskillen when for the first time in Northern Ireland she was able to visit a Roman Catholic place of worship. She has warm relationships with leaders of all churches and is just back from getting to know Pope Francis.
The Irish state visit is another milestone in the maturing of the people of these two islands. Most nationalists have shown generosity towards the royals.
Would it be crazy to believe that in my lifetime unionists would give the Pope the best kind of warm Northern Irish welcome?
Centuries of hatred thawed with significant visit
After 400 years of unrest, bloodshed, distrust, and uneasy coexistence – and eventual resumption of good relations mingled with a great deal of fear and loathing along the way – Queen Elizabeth II opened a new era in the history of these islands when she paid a state visit to the Republic in May 2011.
It was not merely a personal first for Elizabeth. No British monarch had been in the South for 100 years since George V said farewell in 1911.
The oldest and most widely travelled sovereign in history had managed to visit 134 of the world's nations, not to mention most of her dependencies and colonies around the globe. And yet she would have to celebrate her 85th birthday before visiting the United Kingdom's closest neighbour.
In a colossal gesture, which one historian remarked almost rewrote Irish history, the Queen visited the Garden of Remembrance in Dublin – dedicated to all those who died in all the fighting for independence from British rule.
With the Irish tricolour at half mast and the wreaths laid, the Queen, Duke and Irish president paid their respects.
For the large majority of Irish people – and for the Queen's host, President Mary McAleese – the sight of the British sovereign laying a wreath there, bowing her head and marking a minute's silence, was a profound and welcome shift in Anglo-Irish relations.
Even the Queen's few words of Gaelic at the start of her speech at the state dinner in Dublin Castle – "A Úachtárain agus a chairde" ("president and friends", immaculately pronounced) – were an unexpected gesture.
The speech, with its apology for "things we wish had been done differently or not at all", was greeted across the Irish political spectrum with near universal praise.
Her words, calling for forbearance and conciliation and the loosening of the knots of history, striving to create a more harmonious relationship "close as good neighbours should always be", led all the Irish papers.
All were full of praise for the address, which was delivered in front of dignitaries from both sides of the Irish border.
Some Sinn Féin politicians pronounced themselves "underwhelmed" – and found themselves roundly attacked for refusing to meet the Queen.
Gerry Adams, however, united with David Cameron to praise the Elizabeth's historic address. "I believe that her expression of sincere sympathy for those who have suffered as a consequence of our troubled past is genuine," he said.
More than 500,000 viewers in the Republic watched the televised historic visit.