Nemedians

The Nemedians

These were the next race of people to arrive in Ireland after the Partholonians were mysteriously wiped out by a plague, according to the Lebor Gabála, the Book of Invasion. 2,000 Nemedians were said to have died from plague and the rest were forced to leave after the Fomhóire had inflicted a great defeat on them.
Source: http://www.mediatel.lu/team/nmack/mmp_myth_nemedians.html