He decided to invade the north of Ireland which was controlled by the Irish clans.
The first modern Irish "clans" were reformed in the latter half of the 20th century.
This ended in defeat for the Irish clans, and much of their land was seized by the English.
The first modern Irish "clans" were established in the latter half of the twentieth century.
Henry's problem was that many of the Irish clans remained autonomous and outside the control of his administration in Dublin.
Almost as venerable an Irish clan here are the Lawtons.
He did undertake a number of military campaigns against Irish clans who threatened the Pale.
A sept is an English word for a division of a family, especially of a Scottish or Irish clan.
It was hardly surprising, then, if the great Irish clans had started to wonder if they, too, might be able to take on the English power.
In 1162 the restored monastery was attacked and burned to some degree, by Irish clans.