Until 13,000 BCE Ireland and Great Britain were covered by a single ice sheet. Mountains which were already very old and weathered were further ground down into rounded hills with scenic U-shaped valleys. Glacial debris piled up at the edge of the ice, forming ridges which blocked river outflow: lakes backed up which infilled into wetland then peat bog, and Ireland's soggy lowlands emerged. European species driven out by the Ice Age, including humans, now returned across the ice bridge - the snakes didn't care to, and unlike the rabbits no-one saw fit to re-introduce them. The hunting of a bear in 10,500 BCE shows that Ireland by then had hunter-gatherer inhabitants, and the earliest "village" is from 7000 BCE. Some time before 4000 BCE a Neolithic culture emerged with settled agriculture - some of their field systems have been preserved beneath peat bog. Their wooden or wattle-and-daub secular structures have not survived, but what endures is their remarkable ritual landscape of great stone monuments with precise astronomical alignments. At Brú na Bóinne the midwinter sunrise briefly shines upon the inscriptions deep in an underground funeral chamber, but it's simply the best known of many such monuments.
The Bronze Age from 2500 BCE brought wedge tombs, hill forts and metal weaponry, but its finest legacy is the intricate working of gold into jewellery, on display in the National Museum in Dublin. Several fabulous hoards were sacrifices, deliberately lost within the bogs which in that era were rising and engulfing the land. If this was intended to propitiate the gods of climate change, it didn't work, and poor climate, ritual bog causeways and gold sacrifices continued into the Iron Age from 800 BCE. For "iron" read "steel", forged into much stronger weapons and agricultural implements - you could plough new ground or fell timber or set about your neighbours to better effect, and this sparked population shifts across Europe. A Celtic language and culture emerged in Ireland, though it's unclear whether a genetically distinct Celtic people arrived. Great Britain came under Roman rule and its tribes spoke P-Celtic languages forerunners to Welsh and Cornish, while Ireland spoke the Q-Celtic forerunners to Gaelic, which much later spread to Scotland.
Ireland was Christianised from the 5th century, bringing literacy and a connection to Latin culture. Monastic towns were established, becoming centres of learning and literature. The monks composed poetry, wrote down Ireland’s legends and invented several of their own, to give the Irish a bogus back-story in the Biblical lands. The monasteries were attacked by the Norsemen from the late 8th century, but the Norse in turn became Christian and established major settlements in Dublin, Wexford, Waterford, Cork and Limerick. Ireland in this era spread its culture and Christianity to Great Britain and across Europe.
In 1169 a southern chief invited the Anglo-Normans to help with his local feuds, and a large land-grab began. This was mostly in the south and east, so these regions have the richest heritage of medieval stone castles and monasteries built over earlier timber and earthworks. The Normans made fewer inroads elsewhere, and indeed were repulsed from the midlands to cower behind the Dublin palisade. "Beyond the Pale" ruled the Gaelic chiefs, until the Tudors under Elizabeth I resumed the take-over project. The Ulster chiefs held out until 1603, when their power was broken and their lands seized, to be colonised by loyal "Plantations" – as had been done in earlier times, with the crucial difference that the colonists in Ulster were Protestant (often Scots) in a land whose natives were Catholic. This created a sectarian fault line in the north, the tremors of which are felt to this day.
17th century Great Britain was convulsed by the Civil War, creating a power vacuum which enabled a quasi-independent Irish Confederation to emerge, centred on Kilkenny. It lasted six turbulent years then Oliver Cromwell arrived in Drogheda, to destroy that town and massacre its inhabitants. He acquired a taste for both pastimes and marched on to subdue all of Ireland. Britain later restored the monarchy but ousted the Catholic King James II. James had more support in Ireland but lost the Battle of the Boyne and fled to France. It was the cue for more confiscation of lands, and of legal strictures against Catholics, the Penal Laws.
The next great upheaval was the 1798 rebellion, centred on Wexford but with French military landings in Mayo. A rattled London government sought to tighten its grip further and in 1801 created the United Kingdom, henceforth ruling Ireland as a collection of provincial counties or shires with no pretensions to be an independent country. Ireland began to industrialise but remained mostly agricultural, and Irish-speaking outside the cities. Its main grievances were the Penal Laws, harsh land tenure and labour laws, suppression of Irish language (e.g. in school) and minority rule by a Protestant clique. Those that could leave got out, to the industrial cities of England, Scotland and North America, or joined the army. The worst of several famines struck in the 1840s, and the country was eviscerated. The Irish Potato Famine (known in Ireland as just the Great Famine) from 1845–1852 was so devastating that even in the 21st century, the population of Ireland has yet to recover to pre-famine levels.
Following the Great Famine, Irish political movements increasingly identified British administration as the primary cause of Ireland's economic and social hardships, particularly in the southern regions. Nationalist groups argued that Irish culture, language, sports, religion, and agrarian land ownership could only fully develop through self-governance or independence. While the British government introduced several land and political reforms, these were too little, too late, contributing to a period of intense agrarian and political unrest known as the Land War and to subsequent conflicts. Meanwhile in the north, Belfast and its hinterland were staunchly unionist, largely Protestant, and industrial. After several failed attempts, a Home Rule bill was passed by parliament in 1914, nicely in time to be stalled by the outbreak of the First World War. Hundreds of thousands of Irishmen marched away behind the Union Jack to the trenches of Flanders and the Somme.
An armed insurrection broke out in Dublin at Easter 1916, when nationalists seized the main post office and read a proclamation of independence. They had little support and were soon bombarded into surrender, but their trials and executions by firing squad swung sentiment behind them. After the 1918 Armistice, resistance to Britain escalated into a war of independence, but the north was adamantly against Dublin rule. The price of peace in 1921 was partition, with 26 counties joining the Irish Free State (precursor to the present Republic) while six counties in the north-east remained in the United Kingdom as Northern Ireland.
Ireland still had to fight a civil war against those who resisted partition as a betrayal, but "The Troubles" then faded. From the 1960s resentment escalated into a violent conflict in Northern Ireland and its border regions today known as the Troubles, which had little impact on the south, and appears to have been resolved by the Good Friday Agreement of 1998. The Republic remained a poor, agricultural country, neutral during the Second World War. It began to attract tourists in the post-war 20th century, and in 1973 joined the European Community, as did the United Kingdom. From the 1990s Ireland enjoyed an economic boom, and was called The Celtic Tiger, when a low-tax pro-business environment attracted global investment. Much of this was unsustainable; the bubble burst with the recession of 2008.
Along with other Western economies, Ireland has recovered since. More importantly for the traveller it has improved visitor amenities and broadened its image, which for too long was a hackneyed offering of Guinness in Dublin, fishing in the lakes and buying a tea-towel at Blarney Castle. Together with the north, Ireland now portrays itself as the culturally rich, fascinating country that it has been all along.
