On the area where Sean Connolly Barracks now stands, local Gaelic lords, the O’Farrells, built a fortress in the late 1200s. This fortress, or longphort in Irish, gave Longford town its name.
Later, a stone castle, known as Longford Castle, was built. It became the centre of English administration in 1570, when County Longford was created.
A new phase of the castle’s history began in 1620 when Longford town was granted to Francis Aungier during the plantation of the county. Aungier redeveloped the castle, partially turning it into a manor house with gardens and amenities. The town’s market house and market square were established close by on the west side of the castle.
In 1774, Aungier’s relative, the Earl of Longford, sold the castle and leased the surrounding land to the British authorities for the establishment of a cavalry barracks. Gradually, most of the castle was adapted or demolished. The last surviving section of it, including part of a tower, was to the east of the entrance, outside the grounds.
In 1815, the barracks were built and originally used as a main military accommodation building and officers' mess.
In 1922, with the establishment of the Irish State, it was transferred from British to Irish control. It was named after Longford Brigade Brigadier Sean Connolly, who was fatally wounded in action in 1921 by British forces during the Irish War of Independence (1919-21).
The barracks served as a full-time army base from 1972 until 2009.
Today, a market house dating from c1700 still stands within the complex. Part of the site has been adapted for use by County Longford Vocational Education Committee and the complex is currently open for planned events only.
