Giant's Causeway, Northern Ireland. ©: robertprice877 / 123RF Stock Photo
The Twelfth also known as the Battle of the Boyne is an annual public holiday observed in Northern Ireland on July 12th.
If July 12th falls on a weekend, the following Monday will be observed as a public holiday.
Events on the day commemorate the Battle of the Boyne, fought on July 1st 1690 by King William of Orange against King James II. The battle predates the switch to the Gregorian calendar in 1752, which is why it is now celebrated on July 12th.
Before the battle even began, with the forces lined up on opposite banks of the Boyne, an early cannonball strike from James' artillery hit William on the shoulder. A few inches either way and the whole history of Ireland may have been changed. As it was, the injury wasn't serious enough to stop William commanding his troops and winning the day.
The victory of William and his Orangemen was seen as a key moment in the 'Glorious Revolution' when the Protestant (but not very English) William overthrew the Catholic James with the support of the English Parliamentarians.
The day is marked by marches by the Orange Order across Northern Ireland. As a significant proportion of the population of Northern Ireland is Catholic, The Twelfth is an undeniably contentious holiday, with the route of the marches serving as flash points for conflicts between Protestants and Catholics over the years.
On the Eleventh night, huge bonfires are lit in Protestant areas. The tradition is that the bonfires were lit to help King William navigate his way to his landing in Ireland at Carrickfergus Castle. However, the timing of a bonfire tradition so close to Midsummer Day may hint at an older source for the custom.