DYSARTENOS, a parish, partly in the barony of Maryborough East, but chiefly in that of Stradbally, Queen's county, and province of LEINSTER, 3¾ miles (W. by S.) from Stradbally, on the road to Maryborough; containing 1354 inhabitants. This place, at a very remote period, was the residence of the O'Mores, princes of Leix; and also of Dermod McMurrough, king of Leinster. A monastery was founded here by AEngus, on his retirement from Clonenagh abbey, of which he was abbot; but, though it flourished for some time, not even the site is known. The parish is the property of Sir Henry Parnell, Bart., who has fitted up a place of summer residence within the walls of the ancient fortress. Fairs are held here on Whit-Monday, and Get. 12th. The living is a vicarage, in the diocese of Leighlin, united from time immemorial to the vicarage of Kilteel, and in the patronage of Lord Carew, in whom the rectory is impropriate. The tithes amount to £416. 10. 10½., of which £'277'. 13. 11¾. is payable to the impropriator, and the remainder to the viear. The glebe-house was built in 1813, by a gift of £400, and a loan of £360 from the late Board of First Fruits; the glebe comprises seven acres. The church, towards the repair of which the Ecclesiastical Commissioners have lately granted £333, is a small edifice with a square tower, forming a very picturesque object, on the summit of one of the Dysart hills. In the R. C. divisions the parish forms part of the union or district of Maryborough; the chapel is a neat building. About 140 children are taught in a national school, and there is also a Sunday school. The fortress of Dunamase occupies the summit, of a precipitous rock, rising from the midst of an extensive plain and from a very rcmote age was the residence of the O'Mores, and with the territory of Leinster became the property of Sfrongbow, Marl of Pembroke, by marriage with the daughter of Dermod M'Murrough, King of Leinster, and afterwards passed again by marriage to William de Braos, the reputed founder of the castle and manor of Dunamase. ln 1264 it was held by Maurice Fitzgerald, and soon after by Lord Mortimer, during whose absence in England it was, with seven other of his castles, seized by his vassal O'More, to whom he had entrusted it. Lord Mortimer, on his subsequent, recovery of the fortress, increased its strength by additional fortifications; and it was tor a long period an object of continued contests between the English and the native ehict'tains. It was further strengthened in the reign of Jan. I., but was taken in 1641 by the insurgents who were soon after driven out by Sir Chas. Coote; it. afterwards surrendered to Gen. Preston, but. was retaken by the parliamentarians, who in 1646 were expelled by Owen Roe O'Neill, who carried if by assault. In 1649 itwas taken by Lord Castlehaven, but. the year following the garrison surrendered to the parliamentarian forces under Cols. Hewson and Reynolds, by whom it was dismantled and nearly demolished. The remains occupy the summit of a hill200 feet high, and consist of a barbican and watch-tower defending the entrance on the southwest side, on which alone it was accessible; from the barbiean a draw-bridge afforded access to the first gateway, which is defended by two towers. The interior consists of an outer and inner court; and the whole is defended by walls of great thickness surrounding the summit of the hill, which is more than 1000 feet in circuit, fortified at intervals with towers. The ruins of the keep, in which was apparently a chapel, occupy the highest ground; and adjoining it are the remains of the state apartments. Small silver coins of the early Irish kings have been found on the site of the ruins.