"I1-M253 et al has highest frequency in Scandinavia, Iceland, and northwest Europe. In Britain, haplogroup I1-M253 et al is often used as a marker for "invaders," Viking or Anglo-Saxon. The I1b-M227 subclade is concentrated in eastern Europe and the Balkans and appears to have arisen in the last one thousand to five thousand years. It has been reported in Germany, Czech Republic, Poland, Estonia, Ukraine, Switzerland, Slovenia, Bosnia, Macedonia, Croatia, and Lebanon." [1]
Irish lineages of this Scandinavian/Anglo-Saxon haplogroup have a challenge ahead when it comes to determining their surname ancestors' early history. For a discussion about some historical events that may have influenced how some of these Scandinavian families came to Ireland over that last 1000 or so years, see Discoveries > Origins > Immigrants to Ireland.
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1. International Society of Genetic Genealogy (2010). Y-DNA Haplogroup Tree 2010, Version: 5.00, Date: 1 January 2010, http://www.isogg.org/tree/ 4 January 2010.