The Ulster Scots ( Ulster-Scots : Ulstèr-Scotch ), commonly known as Scots-Irish outside of Ireland, are an ethnic group  in Ireland , found mostly in the Ulster region and to a lesser extent in the rest of Ireland. Their ancestors were mostly Protestant Lowland Scottish migrants  the largest numbers coming from the " Border Reivers " culture of the Scottish Borders , from Galloway , and Ayrshire , although some came from further north in the Scottish Lowlands and also to a lesser extent from the Highlands .
These Scots migrated to Ireland in large numbers both as a result of the government-sanctioned Plantation of Ulster , a planned process of colonisation which took place under the auspices of James VI of Scotland and I of England on land confiscated from members of the Gaelic nobility of Ireland who fled Ulster and as part of a larger migration or unplanned wave of settlement.
Ulster Scots emigrated onwards from Ireland in significant numbers to what is now the United States and to all corners of the then-worldwide British Empire —what are now Canada , Australia , New Zealand , South Africa , the West Indies , to British India , and to a lesser extent to Argentina and Chile . Scotch-Irish (or Scots-Irish) is a traditional term for Ulster Scots who emigrated to North America. 
The first major influx of border English and Lowland Scots into Ulster came in the first two decades of the 17th century.
First, before the Plantation of Ireland and even before the Flight of the Earls, there was the 1606 independent Scottish settlement in east Down and Antrim. It was led by adventurers James Hamilton and Sir Hugh Montgomery , two Ayrshire lairds . Montgomery was granted half of Conn O'Neill's land as a reward for helping him escape from prison. Hamilton forced himself in on this deal when he discovered it and, after three years of bickering, the final settlement gave Hamilton and Montgomery each one-third of the land. 
Starting in 1609, Scots began arriving into state-sponsored settlements as part of the Plantation of Ulster . This scheme was intended to confiscate all the lands of the Gaelic Irish nobility in Ulster and to settle the province with Protestant Scottish and English colonists. Under this scheme, a substantial number of Scots were settled, mostly in the south and west of Ulster, on confiscated land.
During the Irish Rebellion of 1641 , the native Irish gentry attempted to extirpate the English and Scottish settlers in revenge for being driven off their ancestral land, resulting in severe violence, massacres and ultimately leading to the deaths of between four and six thousand settlers over the winter of 1641–42. Native Irish civilians were massacred in return. By 1642 native Irish were in de facto control of much of the island under a Confederate Ireland , with about a third under the control of the opposition. However, many Ulster-Scots Presbyterians joined with the Irish in rebellion and aided them in driving the English out. 
The Ulster-Scottish population in Ireland was quite possibly preserved from complete annihilation during the subsequent Irish Confederate Wars , when a Scottish Covenanter army was landed in the province to protect the Ulster-Scottish settlers from native Irish landowners. The war itself, part of the Wars of the Three Kingdoms , ended in the 1650s, with the Cromwellian conquest of Ireland . At the head of the army, Oliver Cromwell conquered all of Ireland. Defeating the Irish Confederates and English Royalists on behalf of the English Parliamentarians , he and his forces employed methods and inflicted casualties among the civilian Irish population that have long been commonly considered by contemporary sources, historians and the popular culture to be outside of the accepted military ethics of the day (see more on the debate here ). After the Cromwellian war in Ireland was over, many of their soldiers settled permanently in eastern Ulster.
Under the Act of Settlement 1652 , all Catholic-owned land was confiscated and the British Plantations in Ireland , which had been destroyed by the rebellion of 1641, were restored. However, due to the Scots' enmity to the English Parliament in the final stages of the English Civil War , English settlers rather than Scots were the main beneficiary of this scheme.
There was a generation of calm in Ireland until another war broke out in 1689, again due to political conflict closely aligned with ethnic and religious differences. The Williamite war in Ireland (1689–91) was fought between Jacobites who supported the restoration of the Catholic James II to the throne of England and Williamites who supported the Protestant William of Orange . The majority of the Protestant colonists throughout Ireland but particularly in Ulster, fought on the Williamite side in the war against the Jacobites . The fear of a repeat of the massacres of 1641, fear of retribution for religious persecution, as well as their wish to hold on to lands which had been confiscated from Catholic landowners, were all principal motivating factors.
The Williamite forces, composed of British, Dutch, Huguenot and Danish armies, as well as troops raised in Ulster, ended Jacobite resistance by 1691, confirming the Protestant minority's monopoly on power in Ireland. Their victories at Derry , the Boyne and Aughrim are still commemorated by the Orange Order into the 21st century.
It was only after the 1690s that Scottish settlers and their descendants, the majority of whom were Presbyterian , gained numeric superiority in Ulster, though still a minority in Ireland as a whole. Along with Catholics , they were legally disadvantaged by the Penal Laws , which gave full rights only to members of the Church of Ireland (the Anglican state church ), who were mainly Anglo-Irish (themselves often absentee landlords ), native Irish converts or the descendants of English settlers . For this reason, up until the 19th century, there was considerable disharmony between Dissenters and the ruling Protestant Ascendancy in Ireland. With the enforcement of Queen Anne's 1703 Test Act , which caused further discrimination against all who did not participate in the established church , considerable numbers of Ulster-Scots migrated to the colonies in British America throughout the 18th and 19th centuries.
Towards the end of the 18th century, many Ulster-Scots Presbyterians ignored religious differences and, along with many Catholic Irish, joined the United Irishmen to participate in the Irish Rebellion of 1798 in support of republican and egalitarian ideals. 
Scots-Irish / Ulster Scots
Just a few generations after arriving in Ulster, considerable numbers of Ulster-Scots emigrated to the North American colonies of Great Britain . Between 1717 and 1775, an estimated 200,000 migrated to what became the United States of America . In the United States Census of 2000, 4.3 million Americans (1.5% of the population of the United States) claimed Scotch-Irish ancestry. Author and former United States Senator Jim Webb suggests that the true number of people with some Scots-Irish heritage in the United States is more in the region of 27 million, possibly because contemporary Americans with some Scotch-Irish heritage may regard themselves as either Irish, Scottish, or "American" instead.   
Over the centuries Ulster Scots culture has contributed to the unique character of the counties in Northern Ireland. The Ulster Scots Agency points to industry, language, music, sport, religion and myriad traditions brought to Ulster from the Scottish lowlands. In particular, the origin of country and Western music was extensively from Ulster Scots folk music. The cultural traditions and aspects of this culture including its links to country music are articulated in David Hackett Fischer 's book, Albion's Seed: Four British Folkways in America .
Most Ulster Scots speak English as a first language . Ulster Scots , the local dialect of the Lowland Scots language, which has, since the 1980s, also been called "Ullans", a portmanteau neologism popularised by the physician, amateur historian and politician Dr Ian Adamson ,  merging Ulster and Lallans —the Scots for "Lowlands"  —but also an acronym for " U lster-Scots l anguage in l iterature a nd n ative s peech". 
The North American ancestry of the X-linked form of the genetic disease congenital nephrogenic diabetes insipidus has been traced to Ulster Scots who came to Nova Scotia in 1761 on the ship Hopewell . 
- British American
- Highland Clearances
- History of Northern Ireland
- History of Scotland
- Immigration to the United States
- Irish Catholic
- Orange Order
- Plantation of Ulster
- Presbyterian Church in Ireland
- Republic of Ireland
- Scotch-Irish American
- Society of United Irishmen
- Ulster Covenant
- Ulster loyalism
- Ulster-Scots Agency
- Ulster Scots language
- Unionism (Ireland)
- William III of England