After the Anglo-Norman invasions of the twelfth century, Laois became a much disputed borderland between the Gaelic Irish and the new arrivals. The Rock of Dunamase became a key bastion of Norman power. Other important castles and forts were built in the county such as Lea Castle, indicating the importance of the county during the medieval period. Towns were also established at this time, but during the turbulent years of the fourteenth century, the Rock of Dunamase and Lea Castle eventually fell back into Irish control.
The sixteenth and seventeenth centuries marked dramatic changes in Laois as this was the era of plantations. The nineteenth century in Laois was marked by agrarian unrest. One of the leading orators striving for tenants rights was James Fintan Lalor who was born at Tinnakill House, Raheen. He was one of the first political thinkers to establish the connection between tenants rights and independence and uttered the immortal words:“Ireland her own, and all therein from the sod to sky. The soil of Ireland for the people of Ireland”. By the twentieth century, a new Ireland was born and Queen’s County was once again named Laois.