The battle of the Boyne: what happened at the July 1690 clash and why is it commemorated on ‘the Twelfth’?

The anniversary of another decisive battle of the Williamite Wars, the 1691 battle of Aughrim, falls on 12 July (its pre-Gregorian calendar anniversary was 22 July), and marks the date when Jacobite forces in Ireland loyal to James were destroyed. The dates of the two battles have been conflated since the 18th century, when loyalist groups began celebrating on 12 July.

What was the background to the battle?

In 1685, James VII of Scotland and II of England had succeeded to the thrones of England, Scotland, and Ireland. His elder brother, Charles II, had no legitimate children, so James became the next Stuart king. James was a Catholic, which made him a figure of suspicion to many Protestants, who held a deep-seated fear of Catholicism (‘popery’) and worried that the king might increase the power and influence of fellow Catholics in Stuart England and Scotland. However, it wasn’t until the birth of the king’s son, also named James, that the threat of a Catholic dynasty led a group of prominent Protestants – the so-called ‘Immortal Seven’ (three earls, a viscount, a bishop and two other noblemen) – to turn to Prince William of Orange. The Dutch prince was James’s nephew, and also married to James’s daughter Mary (who had been brought up Protestant).

On 5 November 1688, William, along with 35,000 soldiers, landed in Torbay, Devon, and took power in the ‘Glorious Revolution’ of 1688 (so-called due to its bloodless nature, though some were injured or killed in anti-Catholic riots sparked by the invasion). The coup established the joint monarchy of William and Mary, while James was overthrown and fled to exile in France.

However, allied with France and the French king Louis XIV (who was an enemy of William III), James believed that he could win back his throne. James attacked what he saw as William’s soft underbelly: Ireland. The Earl of Tyrconnell, the Catholic lord deputy of Ireland who was loyal to James, had mustered a force loyal to the exiled king (known as Jacobites). James landed at Kinsale in March 1689 to lead his supporters, sparking the series of battles later known as the Williamite Wars.

What happened at the battle of the Boyne, how many died, and how long did it last?

James II commanded around 29,000 troops, made up of Tyrconnell’s Irish Catholic forces and French soldiers from Louis XIV. Though he had been advised to abandon Dublin and retreat to a safer position to the south, the exiled king disregarded the advice and instead marched to a key strategic ford near Drogheda, north of Dublin, to meet William’s forces advancing from the north.

By the time William III had landed in Carrickfergus in June 1690, his forces had swelled to 36,000, including some Irish Protestants, as well as Dutch, German and Scottish soldiers and many others. This was the largest invading force Ireland had ever seen.

The battle took place on the banks of Boyne in the early hours of 1 July. William’s forces possessed superior numbers and weapons, as well as greater experience – many of his soldiers were already seasoned through war with France. Though William III himself had a near miss – a bullet grazed his arm during the fray – he remained at the battle site and his forces retained their experienced military commander. After around four hours of fighting, James ordered a retreat and William claimed victory.

Though the battle is often regarded as a bloody and one-sided clash, it was far from a decisive military victory. Around 1,500 soldiers were lost out of around 60,000. Military historian Padraig Lenihan told The Irish Story that losses numbered approximately 1,000 on the Jacobite side, and 500 from Williamite forces. “Those are relatively small casualties,” said Lenihan. “It’s less of one big encounter battle than five or six counter-skirmishes – fairly short sharp clashes over wide swathes of countryside … It’s not a classic encounter battle, when all or most of one army clashes with all or most of another.” Most of the soldiers on either side did not see action, Lenihan explains.

Who won the battle of the Boyne and what happened next?

The forces of William III ultimately proved victorious. After the battle, the remainder of James’s forces dropped back to Dublin, and James himself retreated to France. Though a setback to the hopes of his Irish Catholic base, the retreat was not enough to end support for the former king in Ireland. Over further battles, William also captured the cities of Dublin and Cork, and the battle of Aughrim in 1691 proved a hammer blow for the cause; the nationalists who had supported James saw their hopes for freedom from English rule crushed.

As a consequence, William’s hold on the crown was assured. James and his descendants were excluded; for years Jacobite plots would attempt to restore them.

• Read more about James VII and II’s years in exile

The defeat also had long echoes into the next century, as the Jacobite cause rallied around his grandson Charles Edward Stuart – now best known as Bonnie Prince Charlie. He returned to Britain in 1745 in an attempt to overthrow George II. However, the ‘Young Pretender’ and his forces were ultimately defeated at the battle of Culloden in Scotland in 1746, and Charles fled into exile.

Why do some loyalists in Northern Ireland and Scotland still celebrate the battle of the Boyne?

The Orange Order, a Protestant ‘fraternal’ organisation founded in 1795, still celebrates the victory. The first such commemorations occurred in the late 18th century, and each year on or around 12 July, ‘Orangemen’ march in some communities in Northern Ireland and Scotland in commemoration of ‘King Billy’s’ victory. The events are characterised by marchers wearing bowler hats and sashes, and accompanied by tin whistles and drums. Historically, some of the commemorations have been marred by violence, and critics have called the celebration sectarian and supremacist. They remain contentious, particularly when planned to progress through Catholic neighbourhoods.

To some, William III is still celebrated as a champion of his faith and the man who secured the Protestant ascendancy in Ireland. To others, he is remembered as an oppressor of the Irish and the brutal tyrant who crushed his enemies mercilessly at the battle of the Boyne.

WATCH on BBC iPlayer: The Twelfth Revisited | Helen Mark presents a look back through the archives with some of the historians and commentators who have helped explain The Twelfth, its traditions and spectacle down the years