The FitzGeralds of Leinster were a prominent noble family in Ireland, particularly influential during the medieval period. They were part of the Anglo-Norman invasion of Ireland in the 12th century and established significant power in the province of Leinster. The family played a crucial role in the political landscape, often engaging in conflicts with other Irish clans and the English crown. The FitzGeralds held various titles, including the Earl of Kildare, and were known for their contributions to Irish culture and governance. Their legacy includes the establishment of several towns and castles, which remain historical sites today. The family's influence waned in the 16th century due to political changes and conflicts, but their impact on Irish history is still recognized.