“During the 1650s, over 100,000 Irish children between the ages of 10 and 14 were taken from their parents and sold as slaves in the West Indies, Virginia and New England. In this decade, 52,000 Irish (mostly women and children) were sold to Barbados and Virginia. Another 30,000 Irish men and women were also transported and sold to the highest bidder. In 1656, [Oliver] Cromwell ordered that 2000 Irish children be taken to Jamaica and sold as slaves to English settlers.” http://www.irishcentral.com/roots/history/irish-the-forgotten-white-slaves-says-expert-john-martin-188645531-237793261.html
Some was hatred of the Irish who were considered less than human by the British, some was hatred of Catholicism, and some was profit motive. Muslims were not involved in this slave trade as they were in most.
You can find various sites on the Internet (and in libraries where we used to find things) that deny Irish slavery was like African slavery. Really, as a percentage of the population I think the islands and South America had a higher percentage of Irish than African. They didn’t fare well, but are the founding families of many light skinned African Americans. Between the slavery of the 16th and 17th century and the famine immigration of the 19th century, Ireland’s population was decimated.