- William Conolly, who was Speaker of the Irish House of Commons, was born in Donegal in 1662. He had a yearly income of £25,000 and owned huge estates in about ten counties of Ireland.
- He would have required 240 horses to bring his half year's rent from his house in Dublin to Castletown and three cellars for storage.
- He became so popular and famous that many parents named their children after him.
- William qualified as a solicitor in 1685 and later as a barrister.
- He became rich by acting as solicitor for landlords who sold and bought lands after the Williamite wars. As he was an Irishman and a Protestant, many families chose to sell to him in preference to English landlords.
- He came to Celbridge in 1709 where he purchased 1,730 acres of land. His tenants lived in thatched cabins and he complained that they were all beggars. He insisted that in future they would build houses of stone with chimneys and windows.