The Wicklow Mountains take their name from County Wicklow which in turn takes its name from Wicklow town. The origin of the name is from the Old Norse Wykynglo or Wykinlo. The Irish name for Wicklow, , means Church of Mantan, named after an apostle of Saint Patrick. Wicklow was not established as a county until 1606; before that it had been part of County Dublin. During the medieval period, prior to the establishment of County Wicklow, the English administration in Dublin referred to the region as the Leinster Mountains.