The Mound of Down.

This oval shaped fort situated in the former Quoile marshes just to the north of Downpatrick town, is about 200 meters long and 100 wide, much of its recorded history dates it to the early Christian period, although its origins are much earlier.

When the outer trench was cut the earth was thrown up making an encircling bank which was possibly about six meters high. In earlier times before the Quoile barrier, this trench would have contained water much of the time.

The Mound of Down has a long history, it is likely that it was used as a defendable power base prior to the Christian era, its position in the Quoile marches almost totally surrounded by water making it eminently suitable for this purpose. During the Norse invasions in the eighth and ninth centuries the Mound of Down together with other forts in the area and the fact that the Ulaid tribe maintained a strong naval fleet, played a significant role in preventing the invaders establishing any long term settlements in the area of present day County Down.

By the twelfth century the site was one of the most important in the area and the seat of power of the local chiefs the MacDunleavy, in 1177 Rory MacDunleavy was attacked and defeated by John de Courcy, although de Courcy was vastly outnumbered his forces were much better equipped, the Irish were unable to cope with the Norman armored cavalry, the tanks of the time. The MacDunleavy never recovered from the Battle of Downpatrick, one branch moved to Scotland, while another became physicians to the O'Donnell's of Donegal.

Immediately after his victory de Courcy built a motte at the south end of the fort, this would have had a wooden watch tower, building wooden castle on previously fortified captured sites, was Norman policy enabling them to hold an area until more permanent structures could be built. This was the first of many such castles he was to build in Counties Down and Louth, one year later de Courcy began building Carrickfergus castle.

See also The Development of Castles.