The 10 most popular last names

Click links after each family to see complete clan story and photos

Kellys may have bright heads, but O’Sullivans have hawk-like eyes.

The O'Sullivans or Sullivans are one of the most populous of the Munster families. In Irish, O'Sullivan is O'Sileabhin, and there is no doubt that origin of the name comes from the word sil (eye), though whether it is to be taken as "one-eyed" or "hawkeyed" is in dispute among scholars.

Originally lords of the territory around Cahir, County Tipperary, in the 12th century, they migrated to what is now West Cork and South Kerry, where the name is still very prominent.

READ THE WHOLE STORY OF THE O'SULLIVAN CLAN! CLICK HERE

 4. Walsh – the Welshmen

The meaning of this “Welsh” name is pretty straightforward.

The name Walsh is one of the most common of the Norman associated names found in Ireland. It seems to have been the name used by the many different groups of Welsh people who arrived in Ireland with the Normans during the 12th century.

The name comes from Welsh, which simply means Welshman, and its early Norman form was "Le Waleys." But this became gradually anglicized to Walsh.

READ THE WHOLE STORY OF THE WALSH CLAN! CLICK HERE

5. O'Brien – the noblemen

O’Briens are pretty lucky – they are descended from one of the greatest and most famous Irish kings.

The name O’Brien, also spelled O'Bryan or O'Brian, translates to Ó Briain in Gaelic, which means "of Brian.”

The name indicates descendance from Brian Boru, the celebrated High King of Ireland. This gives O’Briens leave to call themselves “high” and “noble.”

Most O’Briens can be found in Counties Clare, Limerick, Tipperary and Waterford.

READ THE WHOLE STORY OF THE O'BRIEN CLAN! CLICK HERE

 6. Byrne – the ravens

Byrnes can be found flying around all over Counties Wicklow and Dublin.

Byrne, originally O’Byrne, comes from the Gaelic O'Broin meaning "descended from Bran,” an 11th century King of Leinster.

The O'Byrnes were chieftains of what is now County Kildare until the Norman invasion when they were driven from their lands and migrated (ha!) into the mountains of County Wicklow.

There, together with their allies the O'Tooles, they successfully resisted Norman and English domination for centuries.

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Nster.com