- A famous Catholic family called the Aylmers lived at Lyons for about 400 years. In the 1641 Rising, the Earl of Ormonde burned Lyons and the old castle was destroyed and never rebuilt. Even though they were Catholics they were spared by Cromwell and later by King William of Orange. They sold the land to Sir Nicholas Lawless in 1796. The large existing Georgian mansion was built of stone in 1797.
- Nicholas Lawless was the son of Robin Lawless who came from the Wicklow hills and sold turf from an ass and cart on the streets of Dublin. A wool merchant, out of charity, allowed him to pass the bitter winter in his house in Dublin. When the wool merchant died Robin married his widow and became a wool merchant himself. He later became involved in banking and was a very successful businessman.
- Nicholas Lawless had a famous son called Lord Valentine who was a friend of Wolfe Tone, Lord Edward Fitzgerald, Henry Grattan and Daniel O'Connell.
- Valentine was a very progressive farmer. He loved goods of Irish manufacture and this led him to wear green clothes made in Ireland.
- Emily Lawless was the grand-daughter of Lord Valentine who wrote famous poems such as the "Wild Geese" and "Fontenoy". She diedin 1913.
- Mary Lawless was a friend of the Dublin strikers of 1913. She begged of her father to give her a cow to supply milk to those who were locked out. Lord Cloncurry promised her the cow if she would drive it to Dublin herself. Without hesitation the animal was driven to Liberty Hall.
- The house and about half the lands is now the home of the family of the late Tony Ryan (of Ryanair). The other 600 acres is owned by University College, Dublin.