Joe Biden is just the latest in a long line of US presidents to trace their ancestry back to the Emerald Isle.
St. Patrick's Day is typically a day of drinking and revelry, if not reverence for Ireland's patron saint. In this year's subdued celebration environment, a biochemist suggests thanking our livers.
Irish language and culture, not Guinness and Leprechaun costumes, were at the heart of early St Patrick's Day celebrations.
St Patrick chose Ireland over the place of his birth – but where was that exactly?