Today the Taoiseach and the newly-installed First Minister will walk the site of the Battle of the Boyne - an encounter in 1690 which defined the history of this island for the following 300 years. Jonathan Bardon explains what happened
Only for a brief moment in history did Ireland become the cockpit of Europe. That was when James II, the Catholic king driven from his throne in England, decided to make Ireland the base for the recovery of his kingdom with the aid of France.
The raising of a Catholic army in Ireland by the king's lord deputy, Richard Talbot, Earl of Tyrconnell, proved to be the last straw for English aristocrats. In 1688 they turned for help to William of Orange, Stadtholder of the Dutch Republic.
William had every reason to listen to English appeals for aid: he had formed a Grand Alliance against Louis - James I's ally - which included Leopold I, the Catholic Emperor of Austria, several German princes and Pope Innocent XI, an implacable opponent of the French king.
In Ireland, the conflict would be fought strictly along sectarian lines. Elsewhere - with the Pope's encouragement - Protestant and Catholic rulers joined forces to halt the aggrandisement of France.
An imposing Dutch army disembarked at Brixham on November 5th 1688 and James fled to France just before Christmas.
In this so-called Glorious Revolution, the Stadtholder was crowned as William III, joint monarch with his wife, Mary. Meanwhile, Louis provided James with a formidable French army, commanded by the Comte de Lauzun, and on March 22nd 1689 James landed at Kinsale in Co Cork.
From there to Cork city and north to Dublin the Irish turned out to give him a rapturous welcome.
Very soon, King James had control of the whole island - only the island town of Enniskillen in Co Fermanagh and the walled city of Londonderry held out against him. The epic defence of that city over 105 days provided a vital breathing space to William by giving him a secure base in Ulster.
Early in June 1690 William assembled an army of continental size at Hounslow Heath near London. Then a cavalry detachment went ahead to clear the road to Chester for a train of no fewer than 3,000 ox-carts stretching for 18 miles. A squadron of warships escorted William's fleet of about 300 vessels across the Irish Sea into Belfast Lough on June 14th. King William stepped ashore at Carrickfergus and then drove along the lough shore to meet Schomberg in Belfast.
The pale asthmatic monarch told the citizens of Belfast in halting English that the people of Ireland would "be settled in a lasting peace".
James, meanwhile, had stationed his army on the south side of the Boyne close to Drogheda in Co Louth. William advanced south and on Monday June 30th he deployed his troops on the north side of the river. He did not know that that very day the English navy was being badly beaten by the French off Beachy Head in Sussex - there was much at stake in the coming battle.
The international composition of William's army showed how it represented the Grand Alliance: here were regiments of English, Dutch, Danes, French Huguenots, Germans and Ulster Protestant skirmishers ("half-naked with sabre and pistols hanging from their belts . . . like a horde of Tartars", the Williamite chaplain, George Story, remarked).
Numbering some 36,000, the Williamites were at least 10,000 stronger than the Jacobites. Although recently re-equipped by another French fleet, James's army was also greatly inferior in firepower.
William was superstitiously opposed to doing anything important on a Monday, but according to Sir Robert Southwell: "His Majesty, at his arrival yesterday near the river about 12 of the clock, rode in full view of the Irish army, which are ranged upwards on the other side. The enemy even discovered it must be His Majesty . . . They began to fire and presently one of the balls past . . . upon the blade of his right shoulder."
That night the bandaged king had a council of war with his generals. A detachment would ride inland to the fords at Slane, to make it look as if this was the main attack. Later, when the tide was right, he would direct a frontal assault across the river. Just before dawn, on Tuesday July 1st, Meinhard, son of the Duke of Schomberg, led 10,000 men upstream past Townley Hall to the fords at Rosnaree. As the sun rose these Williamites encountered fierce opposition from Irish Jacobite dragoons led by Colonel Sir Neil O'Neill.
O'Neill was mortally wounded and, as the attackers crossed the fords, the French commander made a frantic appeal for assistance. At their headquarters on the Hill of Donore, King James and Lauzun concluded that the main attack was at Rosnaree: they decided to lead most of their troops to the fords. James left those remaining under the command of the Earl of Tyrconnell. And so William's feint to draw most of the Jacobite troops away from the main assault had worked perfectly.
Just after 10am the ground shook as William's artillery pounded the Jacobite positions directly across the Boyne. The Dutch Blue Guards had to wade eight abreast up to their armpits at Oldbridge, holding their weapons over their heads.
King William crossed the river with great difficulty and was temporarily incapacitated by an asthmatic attack. He watched Tyrconnell's Irish Jacobite cavalry counter-attack with great ferocity. The guards swiftly formed squares and Tyrconnell's horsemen dashed themselves futilely against their fixed bayonets. The Williamites triumphed by superior firepower and weight of numbers.
To Southwell's alarm, William "was here in the crowd of all, drawing his swoard & animating those that fled to follow him. His danger was great among the enemye's guns, which killed 30 of the Iniskillingers on the spott".
Near Slane, King James was informed of William's triumph at about two in the afternoon. He and the Marquis de Lauzun decided to abandon the field of battle. In the circumstances, the retreat was brilliantly organised, much credit being due to the Duke of Berwick, James II's 19-year-old illegitimate son, and to Sir Patrick Sarsfield, Earl of Lucan.
The casualties were remarkably low for such a large battle: about 1,000 Jacobites and 500 Williamites died in the action.
King James headed straight for Dublin. He said to Lady Tyrconnell: "Your countrymen, Madam, can run well"; to which she responded: "Not so well as Your Majesty, for I see you have won the race."
Not long after, the deposed king left Ireland for ever, being remembered here as Séamus an Chaca, James the Shit.
The Irish and French retired in good order to fight doggedly behind the Shannon for another year. Not until the Battle of Athlone in June 1691 (the heaviest bombardment in Irish history), the Battle of Aughrim on July 12th (the bloodiest battle in our history, when 7,000 Irishmen died in an afternoon) and the second siege of Limerick (the greatest siege in Irish history) did the Jacobites lay down their arms.
Yet the decisive encounter had been the Battle of the Boyne. The victory was celebrated by the singing of the Te Deum in Vienna and other imperial Catholic cathedrals. Pope Innocent, had died in 1689.For the English, the Glorious Revolution of 1688 and parliamentary rule were made secure. For the Catholic gentlemen of Ireland, the defeat dashed hopes of recovering their estates and ushered in the Penal era. And, for Ulster Protestants, the battle ensured the survival of their plantation and a victory to be celebrated from year to year.
Dr Jonathan Bardon OBE is the author of A History of Ulster. He lectures in history at Queen's University, Belfast.