The following is a list of the main Irish kingdoms and their kings.

The county is known prominently as The Déise after the name of an ancient Irish kingdom which covered a vast part of modern County Waterford.

The four Irish kingdoms eventually broke into five nations under the High King, or Ard Righ.

Historical sources associate these sites with various medieval Irish kingdoms while archaeological investigations show that many royal sites were culturally significant thousands of years before recorded history.

Each Irish kingdom is thought to have had its own royal site, but six sites are considered to be the most important.

Around the year 500, the Irish kingdom of Dal Riata emigrated from Ulster to southwestern Scotland.

According to legend, Sunniva was the heir of an Irish kingdom, but had to flee when a heathen king, who wanted to marry her, invaded.

The following is a list of the kings of West Breifne, an Irish kingdom situated in modern County Leitrim.

"Sir Liam, my lands He far to the east, in the Carpathian Mountains; I harbor no designs on any Irish kingdom."

Thorgest (in Latin Turgesius) was the first Viking to attempt an Irish kingdom.