Athlone Castle was built on abbey land, and in 1214 King John commanded Henry, Archbishop of Dublin, to give the monks a tenth of the expenses of the castle in lieu of the land used, in accordance with the conditions agreed to by the Bishop of Norwich when he was fortifying it. After this there are several references in the State Documents to the tithes and other compensation due to the monks.
In 1221 the King instituted a fair to be held at the castle.
The fortress being situated on the border of Irish territory, its early history has an exceedingly stormy record. In 1226 Geoffrey de Marisco, who was then Justiciary of Ireland, complained that as the King of Connaught refused to come to Dublin, he had appointed to meet him at Athlone, although the castle was fortified against the Crown.
In 1232 an order was issued to Hubert de Burgh to deliver the castle to Peter de Rivall, and the next year one to Richard de Burgh, who was to surrender it to Maurice FitzGerald, Justiciary of Ireland.
Walter de Lacy received twenty marks for the custody of the fortress in 1240, and eleven years later a tax was levied for its repair.
It was granted to Prince Edward, the King’s son, in 1254; and during the years 1276-77 it was repaired.
Richard de Verdon was besieged in the castle in 1288 by Richard de Burgo, and the same year John, Archbishop of Dublin, took up residence there to oversee its better fortification, and to try and make terms with the Irish.
In 1305 Richard de Burgh, Earl of Ulster, was constable.
The castle was “obtained” for the King in 1537, having been in the hands of the Irish for many years. It contained only one piece of broken ordnance, and there is a request that another piece should be sent.
During Queen Elizabeth’s reign it was the residence of the President of Connaught, and also the Chief Justice and Attorney-General for Connaught.