County Offaly which had declined following the Norman Conquest of Ireland. Both Laois (Leix) and Offaly (Uí Failghe) were petty kingdoms in Gaelic Ireland located just outside the Pale (a region around Dublin and the mid east of Ireland that remained loyal to the English Crown following the Norman Conquest). The older kingdoms of Leix and Uí Failghe are not coterminous with the present day counties that were formed. The Kingdom of Uí Failghe from which the name Offaly is derived, was ruled by the Ó Conchobhair Failghe (anglicised as: O'Conor Faly) whose territory extended from the east of the county into
County Offaly Mountain which are the county's second and third highest peaks. Croghan Hill rises from the Bog of Allen and is located in northern Offaly. Although only 234 metres high, it is known for its view over the surrounding area and it stands out by itself. The floodplain of the River Shannon is in the north-western part of the county. The River Camcor runs through the town of Birr and is a Wild Trout Conservation Area. The River Brosna runs across the county from Lough Owel in Westmeath to Shannon Harbour. Silver River runs through several towns in the south of