The county itself was formed following the Tudor plantations of Laois and Offaly in an attempt by the English Crown to expand its sphere of influence in Ireland 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 north Kildare. The Kingdom of Firceall ruled by the O'Molloy clan constituted much of the centre of the county. The Kingdom of Firceall was part of the Kingdom of Meath while Uí Failghe was part of the Kingdom of Leinster. Much of the south of the present day county (as well as northern County Tipperary) was ruled by Ó Cearbhaill of Éile (anglicised as: O'Carroll Ely). Ely formed part of the Kingdom of Munster. These petty kingdoms were swept aside by the Tudor plantations. In 1556, an Act of the Parliament of Ireland created "King's County", named after Philip, the then king of Ireland. This replaced the old Kingdoms with Baronies and the present day County System.