Leinster House was originally the ducal palace of the Dukes of Leinster. Since 1922, it is a complex of buildings, of which the former ducal palace is the core, which house Oireachtas Éireann, its members and staff. The most recognizable part of the complex, and the ‘public face’ of Leinster House, continues to be the former ducal palace at the core of the complex.
Names change and since we are talking history here, we have to refer back to when Leinster House was named Kildare House after James Fitzgerald, the Earl of Kildare, who commissioned it to be built between 1745 and 1747. After bringing this building out to life, Fitzgerald said that fashion will move in the direction that he creates, and we should all never deny that within an unfashionable area in the city, this building made it a desired one. After becoming the Duke of Leinster, the house was then renamed to become the Leinster House.