Eamonn Fitzgerald's Rainy Day

Ireland, 1887: Charles Stewart Parnell's Plan of Campaign is in full swing. Catholic tenant farmers are withholding rents from their Protestant landlords. In an interview with the English Catholic newspaper The Tablet, Arthur Ryan, the administrator of the cathedral of Thurles, says: "Irish priests and bishops bless it [the Plan of Campaign] and declare it to be a high and unassailable morality, a holy war in the cause of the poor and the oppressed."

Holy war! Jihad! Not really. The doctrine of jihad divides the world into the faithful and the infidels but what was happening in Ireland was a power struggle, not a religious war. All Ryan was saying was that the local Catholic Church was siding with the weak against the strong. But little in Ireland is as it seems, so the story contains two of those delicious arabesques that add to the complexity of Irish history: Charles Stewart Parnell, the leader of the Plan of Campaign, was a Protestant, and because the papacy was hostile to Irish agitation against British rule, Pope Leo XIII issued a decree in 1888 condemning Parnell's Plan of Campaign.

Marcus Tanner's Ireland's Holy Wars: The Struggle for a Nation's Soul , 1500-2000, is an account of the role of religion in one small country's tormented history. Tanner is a respected English journalist best known for his book Croatia: A Nation Forged in War and his coverage in the Independent of the Balkan wars of the 1990s. With his combination of journalistic and analytical skills, he brings history to life by using scenes from Irish life today and then rewinding time, explaining the present by means of the past.

The questions Tanner sets out to answer include: Why was Ireland dogged with conflict from the 16th to the 20th century? Why has the northern part of the island been wracked by a hideous campaign of terror and counterterror that still rumbles menacingly on? Why do so many white, Irish Christians who watch the same TV shows, speak the same language and endure the same rainfall want to kill each other?

There's no answering such questions without delving into some very complicated and sanguine history. What emerges from the annals, however, is that the seeds of Ireland's bloodshed were imported, not home-grown, and that much of today's sectarianism stems from the fact that island was used as a battlefield in the strife between Parliament and the monarchy in England, and the related rivalries of European monarchs.

Take the seminal conflict of the late 1680s and early 1690s that followed the decision of the English Parliament to depose the Catholic James II and invite the Dutch Protestant William of Orange to take the throne. It produced the most savage battle ever fought on Irish soil: the Battle of Aughrim in 1691, after which the Catholic elite fled to France and Spain. The Protestant victory that preceded it, the Battle of the Boyne in 1690, is still marked each year in Northern Ireland by the 12th of July marches of the militantly Protestant Orange Order. But William was in Ireland not to smash Catholic unbelievers but to bolster his own tenuous position as a Dutch leader facing an aggressive France. The Williamite alliance more anti-French than anti-Catholic and it included Catholic leaders such as Emperor Leopold I of Austria and the Elector Maximilian of Bavaria. Indeed, William's victory at the Battle of the Boyne, which is celebrated today by Northern Irish Protestants, was welcomed at the time with the singing of a Te Deum in Catholic Vienna and was also greeted by the Pope, whose hatred of Louis XIV far surpassed his sympathy for his followers in Ireland.

Land and power, not religion, were the key issues in the Irish conflicts of the 17th century. The country's tragedy is that religious identity became the pawn of foreign political and economic forces and it has remained hostage to domestic bigots and cynics ever since.

Ireland, 2003: Two headlines from today, 17 March: "Inquiry after police station death" , "A paramedic and two police officers have been injured during disturbances in north Belfast".