The foundation of a university in Dublin was at first attempted by John Leck, archbishop of the see, who in 1311 obtained a bull from Pope Clement V. for its foundation, but it was not accomplished till 1320, when his successor, Alexander de Bicknor, having procured a confirmation of the former bull from Pope John XXII, established a school of learning in St. Patrick's cathedral, for which he framed statutes, and over which he appointed William Rodiart, then dean of St. Patrick's, chancellor. Edward III., in 1358, granted to the scholars his letters of protection; and in 1364 confirmed a grant of land from Lionel, Duke of Clarence, to found a divinity lecture in the university; but, for want of sufficient funds, the establishment gradually declined, though it appears to have lingered till the dissolution of the cathedral establishment, in the reign of Henry VIII.

In 1568, a motion was made in the Irish parliament for its re-establishment, towards which Sir Henry Sidney, then lord-deputy, offered to settle on it lands of the yearly value of £20 and £100 in money. In 1584, Sir John Perrott, lord-deputy, had it in contemplation to re-establish the university by appropriating to its support the revenues of the cathedral of St. Patrick; but in this attempt he was strenuously opposed by Dr. Adam Loftus, Archbishop of Dublin, who made application to Queen Elizabeth and to the lord-treasurer of England for the protection of his cathedral; and also prevailed upon the mayor and citizens of Dublin to give the dissolved monastery of All Saints or All Hallows, on Hoggin (now College) Green, which had been granted to them by Henry VIII., as a site for the intended building.

In 1591, letters patent were issued for the erection of the present establishment, to be styled " Collegium Sanctae et Individuae Trinitatis juxta Dublin, a Serenissima Regina Elizabetha fundatum;" to be a corporate body; under the title of the Provost, Fellows, and Scholars of the College of the Holy and Indivisible Trinity, with power to possess lands to the yearly value of £400, to have a common seal, and to be for ever exempt from local taxes.

The provost and fellows were authorised by it to make laws, statutes, and ordinances for the government of the college, with liberty to select from those of Oxford or Cambridge, at their option; and to grant the degrees of bachelor, master, and doctor in all arts and faculties, provided that all fellows should vacate their fellowships after seven years' occupancy from the time of their taking the degree of master of arts. The first students were admitted in 1593. The funds of the college were so much diminished by the breaking out of the Tyrone rebellion, that the establishment must have been dissolved, had not the queen, in 1601, made the college a further grant of £200 per annum, till it should regain its possessions; and James I. granted it a revenue of £388. 15. English currency, and endowed it with many valuable lands and advowsons in Ulster; he also granted it the privilege of returning two representatives to parliament.

The prosperity of the college was much retarded by internal dissensions, to which the election of the provosts frequently gave rise, and from the want of a more definite constitution to remedy this evil. In 1627 a new code of statutes was framed by Dr. Bedell, afterwards bishop of Kilmore; and in 1633 Archbishop Laud, then chancellor of the university, drew up a more complete code, founded on that of Bedell, which, together with a new charter, was enforced by royal authority, though not without considerable opposition.

By this charter the power of electing the provost, and of enacting and repealing statutes, was vested in the Crown; the fellowships were distinguished into senior and junior, and made tenable for life; the extension of the number of fellows from three to sixteen, and of scholars from three to seventy, which had been previously made, was rendered permanent; and the government of the college was vested solely in the provost and the seven senior fellows, with power to enact bylaws, to be confirmed by the visitors. No subsequent alterations have taken place in the constitution of the college, except an increase in the number of junior fellows. By the Act of Settlement, the chief governor of Ireland, with the consent of the privy council, was empowered to erect another college to be of the university of Dublin, and to be called the King's College, and to raise out of the lands vested in the king by that act a sum not exceeding £2000 per ann. for its endowment.

This clause has never been acted upon; and Trinity College differs in its constitution from those of Oxford and Cambridge, by combining in its own government the full privileges and powers of a university, the provost and senior fellows constituting the only senate or university convocation, and possessing the same power of electing officers and conferring degrees. A new fellowship was founded, in 1698, out of lands bequeathed to the college by Dr. John Richardson, bishop of Ardagh, who had been a fellow. Three others were added in 1724, on the foundation of Erasmus Smith; and five additional fellowships were founded, to be endowed out of the increased revenues of the university, two of them in 1762, and three in 1808. The Senate, or Congregation of the University, by which degrees are publicly conferred, consists of all masters of arts and resident doctors in the three faculties, having their names on the college books, and who are liable to a fine for non-attendance.

The Caput Senatus Academici consists of the vice-chancellor, the provost, or vice-provost, and by election of these, with the consent of the congregation, of the senior master non-regent, resident in the college : they have each a negative voice to prevent any grace for the conferring of a degree from being proposed to the senate. Every grace must first be granted privately by the provost and senior fellows, before it can be proposed to the caput or the senate. There are now two regular days for conferring degrees; namely, Shrove-Tuesday and the Tuesday nearest to the 8th of July, whether before or after. The Board, formed by the provost and senior fellows, meets generally every Saturday to transact all business relating to the internal management of the college.

The following are the principal university and college officers : the chancellor, at present his royal highness the Duke of Cumberland; the vice-chancellor, nominated by the chancellor, at present the Rt. Hon. and Most Rev. Lord J. G. De La Poer Beresford, Archbishop of Armagh, who may appoint a pro-vice-chancellor; the provost, who, except by dispensation from the Crown, must be a doctor or bachelor in divinity, and thirty years of age, at present Bartholomew Lloyd, D. D.; the vice-provost, elected annually by the provost and senior fellows, but who is generally the senior of the senior fellows, and re-elected for many successive years; two proctors, chosen annually, one from the senior and one from the junior fellows, the former being moderator in philosophy for the masters, and the latter for the bachelors, of arts; a dean and a junior dean, chosen annually, the former from the senior and the latter from the junior fellows, and whose duty it is to superintend the morals of the students, and enforce their attendance on college duties; a senior lecturer, chosen annually from the senior fellows, to superintend the attendance of the students at lectures and examinations, and to keep a record of their merits; a censor, created in 1728, whose office is to impose literary exercises in lieu of pecuniary fines upon such students as may have incurred academic censure; a librarian and junior librarian; a librarian of the lending library; a registrar; a registrar of chambers; a bursar and junior bursar; a registrar of the university electors, appointed in 1832 for keeping the register of persons qualified to vote for the university members of parliament; an auditor; six university preachers; and four morning lecturers.

The professorships are seventeen in number. The Regius Professorship of Divinity, originally founded in St. Patrick's cathedral, and held in 1607 by Dr. James Ussher, afterwards Archbishop of Armagh, was more amply endowed in 1674, by Charles II., out of lands given to the college by the Act of Settlement; in 1761 it was made a regius professorship by statute of George III.; and by another, in 1814, its endowment was augmented, and the office made tenable for life. The professor is elected by the provost and senior fellows from the fellows who are doctors of divinity, and vacates his fellowship on his appointment; he acts as moderator in disputations for degrees in divinity, has to preach four times in the year in defence of the Christian religion before the university, to read publicly during the year four prelections in divinity, besides lectures twice every week during term, and to hold an annual examination of the divinity students; he has four assistants.

A lectureship in divinity was founded by Archbishop King in 1718, and was formerly elected to annually from the senior fellows; but this office has been recently separated from a fellowship, and is now held with one of the college livings : its duties also have been considerably increased, and more intimately connected with the education of such students as are preparing for holy orders. Archbishop King's lecturer has now five assistants. Students in divinity must attend with diligence the lectures and examinations of this lecturer and his assistants during the first year of their course, and during the second, the lectures of the Regius Professor and his assistants; without this two years' course of study, no student can obtain the certificates necessary for admission to holy orders. The Regius Professorship of Greek, previously held by a lecturer under the statute of Charles I., was founded in 1761 by statute of George III.; the professor is annually elected, and has two assistants.

Two Professorships of Modern Languages, one for the French and German, and one for the Italian and Spanish, were formed in 1777 by a royal grant of £200 each per ann. The Professorships of Hebrew, Oratory, History, Mathematics, and Natural Philosophy were founded by act of parliament, and endowed by Erasmus Smith; the professors are chosen from among the fellows by the provost and senior fellows, with the approbation of the governors of Erasmus Smith's schools; a lectureship in Mathematics was founded in the middle of the 17th century by Arthur, Earl of Donegal, who endowed it with £10 per annum. The Regius Professorship of Civil and Canon Law was founded in 1668, by letters patent of Charles II., and endowed out of revenues granted to the university by the Act of Settlement; the professor acts also as moderator in all disputations for degrees in law.

The Regius Professorship of Feudal and English Law was founded in 1761, by statute of George III.; the professor is elected by the provost and senior fellows, either for life or for a term of years; he must be a barrister of at least two years' standing, and, if a fellow of the college, may hold the appointment for life, resigning his fellowship. The Regius Professorship of Physic originated in a statute appointing one of the -fellows of the university to devote himself to the study of physic; but since the Restoration, the regius professor of physic and the medical fellow have been regarded as distinct, and, except in two instances, have never been united in the same person.

The Professorships of Anatomy, Chymistry and Botany, originally lectureships established about the year 1710, were founded by an act of the 25th of George III. for the establishment of a complete school of physic in Ireland, in conjunction with three other professorships on the foundation of Sir Patrick Dun's hospital; the professors are elected for seven years, at the end of which time they may be re-elected; they deliver periodical lectures in the theatre of the college. The Lectureship in Natural History was founded by the provost and senior fellows in 1816 : the lecturer, who is also curator of the museum, delivers lectures on such parts of natural history, including geology and mineralogy, as the provost and senior fellows may appoint. The Professorship of Astronomy was founded in 1774, by Dr. Francis Andrews, provost of the college, who bequeathed £3000 for the erection of an observatory, and £250 per annum for the salary of such professor and assistants as the provost and senior fellows should appoint; a statute was obtained, in 1791) for regulating the duties of the professor, who is thereby constituted astronomer-royal for Ireland, and has an assistant, appointed by himself; he resides constantly in the observatory, from which he can never be absent more than 62 days in the year, without leave of the provost or vice-provost.

The Professorship of Political Economy was founded in 1832, by Dr. Whately, Archbishop of Dublin, upon the principle of the Drummond professorship at Oxford; the professor, who must be at least a master of arts or bachelor in civil law, and a graduate of Dublin, Oxford, or Cambridge, is elected for five years : his duty is to deliver lectures in that science to such graduates and undergraduates as may be recommended to him by their tutors, and to print one lecture annually. A Professorship of Moral Philosophy has been recently founded, and annexed to one of the college livings.

The members of the university on the foundation at present consist of the provost, seven senior fellows, eighteen junior fellows, and seventy scholars : the junior fellows are elected as vacancies occur, on Trinity Monday; candidates must have taken at least the degree of bachelor of arts; they are examined on the four last days of the week preceding the election. Only three of the fellows are allowed to be members of lay professions, one of medicine, and two of law, without a dispensation from the Crown; all the rest must devote themselves to the church, and are bound by oath, on their marriage, to vacate their fellowships. The benefices in the gift of the college are 21 in number, and are situated in the dioceses of Armagh, Clogher, Down, Derry, Raphoe, and Kilmore; 17 of them became forfeited to the Crown by the rebellion of O'Nial, and were bestowed on the college by James I.; many of them are of considerable value, and on the death of an incumbent are offered to the clerical fellows in rotation. These benefices, by letters patent of James I., are Arboe, Ardtrea, Clogherney, Clonfeacle, Clonoe, and Desertcreight, in the diocese of Armagh; Aghalurcher, Cleenish, Derryvullen, and Enniskillen, in the diocese of Clogher; Killileagh, in the diocese of Down; Ardstraw, Cappagh, and Drumragh, in the diocese of Derry; Clondehorky, Clondevadock, Conwall, Kilmacrenan, Ramochy, and Tullyaghnish, in the diocese of Raphoe; and Killesandra, in the diocese of Kilmore.

The terms of the university were formerly four in the year, and as altered by Archbishop Laud corresponded nearly to those of Oxford; but by a statute obtained in 1833 they were reduced to three only; Michaelmas, Hilary, and Trinity; but if Easter fall within the limits of Hilary or Trinity term, the term for that year is continued for an additional week. These terms may be kept by answering at examinations held for the purpose, at the beginning of each; but residence, either in the college or in the city, is indispensable for students in divinity, law, and medicine, as terms in these faculties can only be kept by regular attendance on the lectures of the university professors. Members of the university are not required to subscribe to the articles, or to attend the duties, of the church of England, if they profess to have conscientious objections, except on their obtaining a fellowship or scholarship, or on admission to a degree in divinity.

By charter of James I. the university returned two members to the Irish parliament till the Union; after which time it returned only one member to the Imperial parliament, till the recent Reform act, since which it has returned two. The right of election, which was originally vested solely in the provost, fellows, and scholars, has, by the same act, been extended to all members of the age of 21 years, who had obtained, or should hereafter obtain, a fellowship, scholarship, or the degree of Master of Arts, and whose names should be on the college books : members thus qualified, who had removed their names from the books, were allowed six months to restore them, on paying a fee of £2, and such as continued their names, merely to qualify them to vote, pay annually to the college the sum of £1, or a composition of £5 in lieu of annual payment. The number of names restored under this provision was 3005, and at present the constituency amounts to 3135. The provost is the returning officer.

The buildings of the university, which, from their extent and magnificence, form one of the principal ornaments of the city, consist of three spacious quadrangles, erected chiefly after designs by Sir William Chambers. The principal front, which occupies the whole of the eastern side of College-green, is 380 feet long, built of Portland stone, and consists of a projecting centre, ornamented with four three-quarter Corinthian columns supporting an enriched cornice and pediment, under which is the principal entrance; and at each extremity of the facade is a projecting pile of square building, decorated with duplicated pilasters of the same order, between which is a noble Venetian window, enriched with festoons of flowers and fruit in high relief; and above the cornice, which extends along the whole of the front, rises an attic surmounted by a balustrade.

The entrance is by an octangular vestibule, the ceiling of which is formed of groined arches : it leads into the first quadrangle, called Parliament-square, from its having been rebuilt chiefly by the munificence of Parliament, which granted at different times £40,000 for the purpose. This quadrangle, which is 316 feet in length and 212 in breadth, contains, besides apartments for the fellows and students, the chapel, the theatre for examinations, and the refectory. The chapel, which is on the north side, is ornamented in front by a handsome portico of four Corinthian columns, supporting a rich cornice surmounted by a pediment; the interior is 80 feet in length, exclusively of a semicircular recess of 20 feet radius, 40 feet broad, and 44 feet in height; the front of the organ gallery is richly ornamented with carved oak.

The theatre, on the south side, has a front corresponding exactly with that of the chapel, and is of the same dimensions; the walls are decorated with pilasters of the Composite order, rising from a rustic basement; between the pilasters are whole-length portraits of Queen Elizabeth, the foundress, and of the following eminent persons educated in the college; Primate Ussher, Archbishop King, Bishop Berkeley, William Molyneux, Dean Swift, Dr. Baldwin, and John Foster, Speaker of the Irish House of Commons : there is also a fine monument of black and white marble and porphyry, executed at Rome by Hewetson, a native of Ireland, at an expense of £2000, erected to the memory of Dr. Baldwin, formerly provost, who died in 1758, and bequeathed £80,000 to the university.

The refectory is a neat building, ornamented with four Ionic pilasters supporting a cornice and pediment over the entrance; a spacious ante-hall opens into the dining-hall, in which are portraits of Henry Flood, Lord Chief Justice Downes, Lord Avonmore, Hussey Burgh, Lord Kilwarden, Henry Grattan, the Prince of Wales (father of George III.), Cox, Archbishop of Cashel, and Provost Baldwin. Over the ante-hall an elegant apartment has been recently fitted up for the Philosophy school, and furnished with a valuable collection of philosophical and astronomical instruments; and in it are delivered the public lectures of the professors of natural philosophy and astronomy.

The second quadrangle, called the Library-square, is 265 feet in length and 214 feet in breadth. Three sides of it are occupied by uniform ranges of brick building, containing apartments for the students; these are now the oldest buildings in the college and are fast verging to decay. The fourth side is formed by the library, a very fine building of granite, the basement story of which forms a piazza extending the whole length of the square, above which are two stories surmounted by an enriched entablature and crowned with a balustrade. It consists of a centre and two pavilions at the extremities : in the western pavilion are the grand staircase, the Law school, and the librarian's apartment; from the landing-place large folding doors open into the library, a magnificent gallery, 210 feet in length, 41 feet in breadth, and 40 feet high; between the windows on both sides are partitions of oak projecting at right angles from the side walls, and forming recesses in which the books are arranged; the partitions terminate in fluted Corinthian columns of carved oak, supporting a broad cornice, surmounted by a balustrade of oak richly carved, and forming a handsome front to a gallery which is continued round the whole of the room.

From the gallery rises a series of Corinthian pilasters between a range of upper windows, supporting a broad entablature and cornice; at the bases of the lower range of pilasters are pedestals supporting busts, finely executed in white marble, of the most eminent of the ancient and modern philosophers, poets, orators, and men of learning, including several distinguished members of the university. At the extremity of this room is an apartment, in a transverse direction, 52 feet in length, fitted up in similar style, and containing the Fagel library, over which, and communicating with the gallery, is the apartment for MSS., containing records illustrative of Irish and English history of great value, works in the Greek, Arabic, and Persian languages, and some richly illuminated, bibles and missals : the magnificent collection comprises upwards of 100,000 volumes.

To the north of the Library-square is the third quadrangle, of modern structure, but with few pretensions to architectural elegance. It is wholly appropriated to chambers for the students, which occupy two of its sides, the other two being formed by the rear of the northern range of the Library-square and by one side of the dining-hall. A temporary building near its centre contains the great bell, formerly suspended in a steeple which made part of the ancient chapel of the college; it was intended by the original design of the first or principal quadrangle to be erected in a dome over the gateway. The old chapel and belfrey occupied the vacant space between the first and second quadrangles.

An additional square, to contain suites of apartments for students, is laid out and the buildings of one side of it commenced, eastward of the Library-square, part of which is to be taken down when the new range of buildings is finished. The University Museum, a handsome apartment 60 feet long and 40 feet wide, is immediately over the vestibule of the entrance from College Green; it comprises, under the superintendence of a curator, several collections of minerals, of which there are more than 9000 specimens. The Printing-office, founded by Dr. Stearne, Bishop of Clogher, is a handsome structure with an elegant portico of the Doric order, and is situated on the east of the Library-square. To the south of the library is a fine garden for the fellows; and to the east of the College buildings is the Park, comprising about 20 acres, planted and tastefully laid out for the use of the students. Beyond the park are the Chymical Laboratory and the School of Anatomy: this range of building, which is 115 feet in length and 50 feet in breadth, contains a chymical laboratory and lecture-room, with apartments for the professor, a dissecting-room extending the whole length of the building, and an anatomical lecture-room, 30 feet square; an anatomical museum, 30 feet long and 28 feet wide, in which was a valuable collection of preparations of human, comparative, and morbid anatomy, the largest and by much the most valuable part of which, being the private collection of Dr. Macartney, the present professor, has been sold by him to the university of Cambridge.

The Provost's house, a spacious and handsome edifice, is to the south of the west front of the university, and is skreened from Grafton-street by a high wall with a massive gateway in the centre. The College Botanic Gardens are situated in the south-eastern extremity of the city, near Ball's bridge, and comprised originally about four acres, to which two more have been lately added; they are enclosed towards the public road into the city by a dwarf wall of granite surmounted by a very high iron palisade, were first laid out in 1807, and contain an extensive collection of plants well arranged and kept in excellent order. The College Observatory is situated on Dunsink-hill, in Castleknock parish, about 4 miles to the north-west of the city.

The building fronts to the east, and consists of a centre and two receding wings, the former surmounted by a dome which covers the equatorial room, and is move-able, having an aperture two feet six inches wide, which can be directed to any part of the horizon; around the dome is a platform, which commands an extensive and varied prospect. The first professor was Dr. Ussher, senior fellow of Dublin college, under whose direction the building was erected, and who was succeeded, on his death in 1792, by the late learned and ingenious Dr. Brinkley, afterwards Bishop of Cloyne; after whose death, in 1835, the present astronomer-royal of Ireland, Sir William Rowan Hamilton, was appointed.