 Over the century that followed , Norman feudal law gradually replaced the Gaelic Brehon Law so that by the late 13th century the Norman @-@ Irish had established a feudal system throughout much of Ireland . Norman settlements were characterised by the establishment of baronies , manors , towns and the seeds of the modern county system . A version of the Magna Carta ( the Great Charter of Ireland ) , substituting Dublin for London and Irish Church for Church of England , was published in 1216 and the Parliament of Ireland was founded in 1297 . 
