Black Fort ringfort taken from an 1840s Ordnance Survey map can still be seen today. Most ringforts in Ireland are over 1000 years old.
There is ancient evidence for settlement in the Castlebar area. Since people traded, hunting and gathering for a more sedentary lifestyle in the Neolithic Period, Lough Lannagh and the Suire (now called Castlebar) River would have been used for transport and fishing. There have been crannogs and ringforts identified in the surrounding area. In medieval times Clan Quinn, the dominant family in the area would have used these structures from which to rule the surrounding area. It is this Clan that lends its name to the Parish to which Castlebar belongs. Aglishcowane or Aglishclinacuain means ‘Church of Clan Quinn’.
The Norman invasion of 1169 is one of the most significant events in Irish history. Strongbow and later Henry II led their Norman armies to victories firstly in Leinster and Munster and eventually reached Mayo in the form of the de Burgo family by 1235 and ousted the Quinns. With the de Burgos, were the lower ranked de Barris who built a castle close to the river from which the town derived its name, Barry’s castle; Castlebar. The castle (Caslen an Barrag) and its lands are mentioned in the Annals of the Connacht, having been burnt down in 1412. The castle was the focus of much faction fighting between various clans such as the O’Connors, Fitzgeralds, de Burgos and the de Cogans among others, throughout the Late Medieval Period and up until the arrival of Sir Richard Bingham. This marks the beginning of the colonial period in Irish history. It is from this castle and the subsequent settlement around it that Castlebar develops as a town; a town with a very colonial beginning.