In the 15th century the Pale became the only real piece of Ireland under the control of the English King's Dublin government and a tenuous foothold for the English on the island of Ireland.
The Pale boundary essentially consisted of a fortified ditch and rampart (the word "pale" has etymological links with palisade) built around parts of the medieval counties of Louth, Meath, Dublin and Kildare, actually leaving half of Meath and Kildare on the other side.
Within the confines of the Pale the leading gentry and merchants lived lives not too different from that of their counterparts in England, except that they lived under the constant fear of attack from the Gaelic Irish.