Irishman Brian Boru, who led his soldiers to victory against the Vikings in the Battle of Clontarf in 1014, was said to have pitched camp before the confrontation on the site of Mountjoy Square. Playwright Sean O'Casey lived here, at No. 35, and used the square as a setting for The Shadow of a Gunman. Built over the course of the two decades leading up to 1818, this Northside square was once surrounded by elegant terraced houses. Today only the northern side remains
intact. The houses on the once derelict southern side have been converted into apartments.