The Duke of Leinster is a title in the peerage of Ireland, historically associated with the province of Leinster. The title was first created in 1766 for James FitzGerald, the 20th Earl of Kildare. The Duke's family, the FitzGeralds, played a significant role in Irish history, particularly during the 16th and 17th centuries. The current Duke of Leinster is Charles FitzGerald, who holds the title as the 8th Duke. The family seat is Kilkea Castle, located in County Kildare. The Duke of Leinster is one of the most prominent titles in Ireland, symbolizing nobility and heritage.