In 1402 the O'Byrne clan of County Wicklow, who periodically raided Dublin, moved a large mercenary force to the banks of the River Dargle at Bray, but, as the direct route to the city would bring them close to the stronghold of Carrickmines, they apparently hesitated before attacking.
As a major fortress, it had an extensive curtain wall flanked by towers protecting an area of some acres.