KILLOSSORY, a parish, partly in the baronies of BALROTHERY and NETHERCROSS, but chiefly in the barony of COOLOCK, county of DUBLIN, and province of LEINSTER, 3 miles (N. W. by N.) from Swords, on the road from Dublin to Drogheda ; containing 380 inhabitants. It comprises 2483 statute acres, as applotted under the tithe act ; the land is of good quality, and the system of agriculture improving. The principal seats are Rathbeale, the residence of E. T. Corbally, Esq., a spacious mansion, situated in an improved demesne commanding some fine views ; Rawlestown, of J. W. Stubbs, Esq. ; Lays, of P. Aungier, Esq. ; and Lispopple, of M. O'Reilly, Esq. Here is a station of the constabulary police. The parish is in the diocese of Dublin ; the rectory is appropriate to the economy fund of the cathedral of St. Patrick's, Dublin, and the curacy forms part of the union of Swords: the tithes amount to £161. 19. 4-., payable to the economy fund. The church is in ruins. In the R. C. divisions it is the head of a union or district called Rolleston, comprising also the parishes of Clonmethan, Kilsallaghan, and Palmerstown, and containing two chapels, situated respectively at Rolleston in this parish, and at Oldtown in Clonmethan. The font of the old church was removed to that of Swords, on the demolition of which it was removed to the R. C. chapel of this parish, where it is still preserved. Near the ruins of the old church a school-house was erected in 1823. There are some remains of the ancient castle of Bragil, which with the manor was granted by Jas. I. to Sir Richard Bolton, chancellor of Ireland, in whose family it still remains. It was defended, during the absence of her husband, by Lady Bolton, against Ruah O'Neill, by whom it was burnt, and Lady Bolton perished in the flames : considerable portions of the interior walls are yet standing, but the outworks have been long levelled.