The 'Old English' were descendants of the Anglo Normans who arrived in Ireland in the twelfth and thirteenth centuries.
The Old English included such powerful families as the Fitzgeralds of Kildare, the Fitzgeralds of Desmond and the Butlers of Ormond.
The English authorities consistently forbade the Old English to adopt Gaelic customs and intermarry with the Irish but most Old English families disobeyed these orders.
Some Old English families were said to be 'more Irish than the Irish themselves' by 1500.
The Fitzgeralds of Kildare dominated Irish politics until after the Kildare Rebellion in 1534.
Two rebellions by the Fitzgeralds of Desmond ended in their downfall and the plantation of their confiscated lands in Munster in the late sixteenth century.
The Butlers of Ormond frequently enjoyed royal favour and considerable power throughout the early modern period.
Some Old English families surrendered to the Crown and conformed to the Protestant faith during and after the Reformation but many refused and lost their lands in the various confiscations and plantations.