ABERGUILLY (ABER-GWILI), a parish, in the lower division of the hundred of ELVET, county of CARMARTHEN, SOUTH WALES, 2 miles (E. by N.) from Carmarthen, on the road from that town to Llandilo-Vawr, containing 2675 inhabitants. This place, which is principally distinguished for an ancient collegiate church, and for its palace, which is the residence of the diocesan, derives its name from its situation on the river Guilly, near its junction with the Towy. About the year 1020, a desperate battle was fought near the village, between Llewelyn ab Seisyllt, Prince of Wales, and Rhin, a Scottish adventurer, who, pretending to be the son of Meredydd ab Owen, obtained the assistance of several powerful chieftains of South Wales, the disaffected subjects of Llewelyn, and assembled an army sufficiently strong to hazard an engagement. Llewelyn, returning from North Wales, at the head of his own forces, hastened to attack the adventurer, and, after a long and obstinate conflict, obtained a complete victory over the rebels, and slew their leader in the pursuit. The village is pleasantly situated, and the meadows in the neighbourhood are watered by the rivers Towy and Guilly, over which last is a neat substantial stone bridge of three arches. The parish abounds with roofing slate of excellent quality, of which there are two quarries at present open, affording employment to about fifty persons, and furnishing an abundant supply of that material for the use of the surrounding neighbourhood. Petty sessions for the division are held here once a month. The living is a discharged vicarage, in the arch-deaconry of Carmarthen, and diocese of St. David's, rated in the king's books at £3. 6. 8., endowed with £200 private benefaction, and A200 royal bounty, and in the patronage of the Dean and Canons of Windsor, but, from his residence in the parish, the Bishop of St. David's is by courtesy allowed to present. The church, dedicated to St. Maurice, and situated near the bank of the Towy, was made collegiate by Dr. Beck, Bishop of St. David's, in 1287, for twenty-two prebendaries, four priests, four choristers, and two clerks. In 1334, some alterations were made by Bishop Gower, who added a precentor, chancellor, and treasurer; and the establishment, the revenue of which was £ 42 per annum, was finally removed by Henry VIII. to his newly-erected college at Brecknock. The church is a neat plain building, consisting of two aisles, without either tower or steeple, having a small belfry placed over the west end for the reception of two bells: it is divided internally by a range of pointed arches and massive octagonal columns. In the churchyard, which is finely planted with evergreens, and is preserved in excellent order, is a monumental stone to the memory of Dr. Adam Ottley, bishop of the diocese, who died on the 4th of October, 1723. At Llanvihangel-uwch-Guilly is a chapel, formerly a chapel of ease, but recently endowed with £ 1200 royal bounty, and erected into a perpetual curacy, in the patronage of the Vicar of Aberguilly. There are places of worship for Baptists, Independents, and Methodists. An endowment of 6 per annum has been made by some unknown benefactor, for the instruction of twelve poor children of the parish. The episcopal palace is pleasantly situated on the banks of the Towy, the meanderings of which through the grounds impart to it considerable beauty and interest, but, from the lowness of its site, it commands no extensive prospects: the scenery immediately surrounding it is cheerful and pleasingly varied, and the mansion, which had been suffered to fall into decay, has been almost entirely rebuilt, in the Elizabethan style, at the expense of the present bishop, and is now one of the most complete episcopal palaces in the kingdom. Cwm Guilly, the seat of Grismond Philipps, Esq., whose father represented the borough of Carmarthen in several parliaments; and Galt y G6g, the property of George Morgan, Esq., are pleasantly situated in the neighbourhood; in which also are the ruins of Castel Pig-gin, formerly the residence of the late Capt. Bloom. Within a short distance of the village, and about four miles from Carmarthen, at a place called White Mill, is Merlin's Grove, a thick wood rising abruptly from the turnpike-road, celebrated as the place of residence of that renowned sage, and also as the place of his interment; the name is now usually applied to a neat family residence situated near it. In a sequestered spot on this farm, near the extremity of the wood, the prophet is said to have been interred, and to have resided in a cavern situated nearly in the centre of the wood, the supposed scene of his incantations, to which allusion is made by Spencer, in his "Faery Queene." In this parish is the lordship of Vynne, belonging to the Bishop of St. David's, and possessing some peculiar privileges, among which are those of holding a court leet, choosing a portreeve and appointing constables, and collecting tolls for the repair of its roads, which are kept in order independently of the parish rate; but it does not maintain its own poor, as an independent township, nor does it differ in any other respect, from the rest of the parish. The average annual assessment for the support of the poor amounts to 41231. 16.