County Offaly is a county in Leinster, Ireland, bordered by seven other counties: Galway, Roscommon, Westmeath, Meath, Kildare, Laois, and Tipperary. Originally the name referred to the Kingdom of Uí Failghe. The present county was shired in 1556 by Mary I of England during one of the Plantations of Ireland, and was then named King's County after King Philip II of Spain, and the county town was Philipstown (now called Daingean) until the nineteenth century. The county town is now Tullamore. Its former name of "King's County" is still used when the title deeds to a property are transferred from a buyer to a seller today.
The southern part of the county is occupied by the Slieve Bloom Mountains, the northwestern part is the floodplain of the River Shannon and the remainder consists of large bogs including the Bog of Allen and Boora Bog.