Brian

A name known both in Ireland, where it has been very popular, and also in Britain, where it was introduced from Brittany. The origin of the name is disputed but may be linked to the Brennus/Brenos cited in battle by Celtic raiders in the Mediterranean in late Roman times. The best-known Brian, from whom the O'Briens [Irish Uí Bhriain] take their name, is Brian Bórama or Boru.