The Earl of Rosse is a title in the peerage of Ireland, created in 1806. The title is associated with the town of Parsonstown in County Offaly, where the family has a long history. The most famous holder of the title was the third Earl, William Parsons, who was an accomplished astronomer and built the Leviathan of Parsonstown, the largest telescope of its time. The current Earl of Rosse is a member of the Parsons family, which has been influential in Irish history and science. The family estate, Birr Castle, is known for its beautiful gardens and historical significance, attracting visitors interested in both nature and heritage.