Irishmen are a group of people who trace their ancestry to the island of Ireland. They are also known as CELTS and GAELS, both of which are five-letter terms used to describe the Irish people. CELTS are an ancient Indo-European people who lived in parts of Europe and the British Isles, while GAELS are a group of people who speak the Goidelic languages, which are native to Ireland, Scotland, and the Isle of Man.