It'll take a bit of time to dig up my reference, but The English crown issued slaving patents for Counties Kerry & Cork in Ireland, sometime in the middle 1500s. They were revoked after about 15-20 years, when the slavers (English) started taking members of the ascendancy of the day (Anglo/Norman-Irish). Slaving was a popular commercial venture there long before the English turned it into big business. When talking about St Patrick, you can never be really sure where to draw the line between fact and fiction, but most accounts consider that he first came to Ireland as a slave. And then, of course, Cromwell profited handsomely selling Irish folk in "the barbadoes." Without getting over-wrought about racial or ethnic injustice, it's probably more productive to consider slavery as an aspect of the corruption wrought by near absolute power.