[1] Roscommon was the homeland of the Connachta dynasty, and included such kingdoms as Uí Maine, Delbhna Nuadat, Síol Muirdeach, and Moylurg.

It was built in 1269 by Robert de Ufford, Justiciar of Ireland, on lands he had seized from the Augustinian Priory.

By 1340 the O'Connor's regained possession of it, and, except for a few brief intermissions, they held it for two centuries until 1569, when Sir Henry Sidney, Lord Deputy seized it.

Two years later the interior was remodelled and large mullioned windows were inserted in the towers and curtain walls.

It remained in Irish hands until 1652 when it was partially blown up by Cromwellian "Ironsides" under Commissary Reynolds, who had all the fortifications dismantled.

A symmetrical moat some distance from the curtain walls surrounded the entire castle and safeguarded it.

Roscommon County Museum and Tourism Office is located next to Harrison hall in the town square.

It was founded just over 750 years ago by King Felim O'Connor (Irish: Fedlimid Ó Conchobair) of Connacht, who was buried there himself in 1265.

The tomb front supporting his effigy slab (but not originally belonging to it) bears eight niches containing fifteenth-century carved figures of gallowglasses, mercenaries of Scottish origin who played a major role in Irish wars of the Later Middle Ages.

But the main part of the church must have survived these misfortunes, for much of its existing fabric dates from the thirteenth century, as seen in the style of the lancet windows in the north and south walls.

Suppressed at the Reformation, the ruined buildings were denuded of their majestic tower, and probably also of the cloister to the south, when they served as a handy stone-quarry for their owner.

It was built in 1832 adjacent to the new gaol (now the site of Roscommon garda station) to replace the previous courthouse, which is now known as Harrison Hall and which currently houses a branch of the Bank of Ireland.

Roscommon County Library is situated in Abbeytown opposite the CBS secondary school.

[19] Roscommon Barracks is located at the south end of the town, close to the railway station.

It became vacant when the police barracks was moved to the site of the disused gaol beside the courthouse on Abbey Street, and in 1907 it was purchased for use as a residence by William and Mary Jane Black.

Over the main door is a fine example of mosaic, carried out by the Italian firm of Salviate, depicting two bishops of the diocese of Elphin connected with the building of the church.

The interior is equally impressive and contained a replica of the Cross of Cong, the original of which was made in Fuerty between 1120 and 1123.

The workhouse building was constructed in 1840, in response to a sudden increase in extreme poverty and famine in the Roscommon town area.

This situation was reflected in a notice which was posted outside Roscommon Workhouse in January 1847, which stated that no new applicants seeking assistance could be admitted.

Major national roads lead from Roscommon to Sligo, Longford, Athlone, Castlebar, Galway and Dublin.

M 788.12: The law of St. Comman [was promulgated] by Aeldobhair, i.e. Abbot of Ros Commain, and by Muirgheas, throughout the three divisions of Connaught.

M 872.2: Aedh, son of Fianghus, Abbot of Ros Comain, bishop and distinguished scribe [died].

LC 1265.6: Fedhlim, son of Cathal Crobhderg Ó Conchobhair, king of Connacht—the protector and supporter of his own province, and the protector of his friends on every side; the plunderer and extirpator of his enemies wherever they might be; a man full of bounty and prowess; a man full of distinction and honor in Erinn and Saxon-land—died after the triumph of unction and penitence, and was interred in the monastery of the Friars Preachers in Ros-Comain, which he had previously granted to God and the Order.

Conchobhar, the son of Ó Conchobhair Ruadh, went out from the court that day, and the ambuscaders attacked himself and his people on all sides; and they were driven to the monastery and their horses were taken from them before the door; and they themselves went into the belfry.

Conchobhar, son of Toirdhelbhach Ruadh Ó Conchobhair, was killed there, and ten and eleven of his people along with him; and horses were taken from them.