thumb|upright=2|Aerial view of many of the colleges of the University of Oxford
The University of Oxford has 36 colleges, three societies, and four permanent private halls (PPHs) of religious foundation. The colleges and PPHs are autonomous self-governing corporations within the university.
These colleges are not only houses of residence, but have substantial responsibility for teaching undergraduate students. Generally tutorials (one of the main methods of teaching in Oxford) and classes are the responsibility of colleges, while lectures, examinations, laboratories, and the central library are run by the university. Students normally have most of their tutorials in their own college, but often have a couple of modules taught at other colleges or even at faculties and departments. Most colleges take both graduates and undergraduates, but several are for graduates only.
Undergraduate and graduate students may name preferred colleges in their applications. For undergraduate students, an increasing number of departments practise reallocation to ensure that the ratios between potential students and subject places available at each college are as uniform as possible. For the Department of Physics, reallocation is done on a random basis after a shortlist of candidates is drawn upon and before candidates are invited for interviews at the university.
For graduate students, many colleges express a preference for candidates who plan to undertake research in an area of interest of one of its fellows. St Hugh's College, for example, states that it accepts graduate students in most subjects, principally those in the fields of interest of the fellows of the college.
A typical college consists of a hall for dining, a chapel, a library, a college bar, senior, middle (postgraduate), and junior common rooms, rooms for 200–400 undergraduates, and lodgings for the head of the college and other dons. College buildings range from medieval to modern, but most are made up of interlinked quadrangles or courtyards, with a porter's lodge controlling entry from the outside.
The first modern merger of colleges was in 2008, with Green College and Templeton College merging to form Green Templeton College. The number of PPHs also reduced when Greyfriars closed in 2008 and when St Benet's Hall closed in 2022. Reuben College, established in 2019, is the first new Oxbridge college since 1990, when Kellogg College was established. There is also a long-term plan to establish another new postgraduate college in conjunction with the redevelopment of Warneford Hospital in east Oxford, with a planning application lodged in August 2025.
right|thumb|[[Brasenose College, Oxford|Brasenose College in the 1670s]]
History
right|alt=Timeline of Oxford Colleges
The collegiate system arose because Oxford University came into existence through the gradual agglomeration of numerous independent institutions. Over the centuries several different types of college have emerged and disappeared.
Monastic halls
The first academic houses were monastic halls. Of the dozens established during the 12th–15th centuries, none survived the Reformation. The modern Dominican permanent private hall of Blackfriars (1921) is a descendant of the original (1221), and is sometimes described as heir to the oldest tradition of teaching in Oxford.
Academic halls
As the university took shape, friction between the hundreds of students living where and how they pleased led to a decree that all undergraduates would have to reside in approved halls.
What eventually put an end to the medieval halls was the emergence of colleges. Often generously endowed and with permanent teaching staff, the colleges were originally the preserve of graduate students. However, once they began accepting fee-paying undergraduates in the 14th century, the halls' days were numbered. Of the hundreds of Aularian houses (from the Latin for "hall") that sprang up, only St Edmund Hall (c. 1225) remains.
Colleges
The oldest colleges are University College, Balliol, and Merton, established between 1249 and 1264, although there is some dispute over the exact order and precisely when each began taking students. The fourth oldest college is Exeter, founded in 1314, and the fifth is Oriel, founded in 1326.
Women's colleges
Women entered the university in 1879, with the opening of Lady Margaret Hall and Somerville College, becoming members of the University (and thus eligible to receive degrees) in 1920. Other women's colleges before integration were St Anne's, St Hilda's and St Hugh's. In 1974 the first men's colleges to admit women were Brasenose, Hertford, Jesus, St Catherine's and Wadham. By 2008 all colleges had become mixed, although one of the Permanent Private Halls, St Benet's Hall, did not start to admit postgraduate women until Michaelmas term 2014 and women undergraduates until Michaelmas 2016.
Postgraduate and mature colleges
Some colleges, such as Kellogg, Linacre, Nuffield, St Antony's, St Cross and Wolfson only admit postgraduate students. All Souls admits only fellows. Harris Manchester is intended for "mature students" with a minimum age of 21. The newest college of the University, Reuben College, was established in 2019 as graduate-only, enrolling its first students in 2021 using the premises of the Radcliffe Science Library.
Societies
Kellogg, Reuben and St Cross are the only Oxford colleges without a royal charter. They are officially societies of the university rather than independent colleges and are considered departments of the university for accounting purposes.
Private halls
The Oxford University Act 1854 and the university statute De aulis privatis (On private Halls) of 1855, allowed any Master of Arts aged at least 28 years to open a private hall after obtaining a licence to do so. One such was Charsley's Hall.
Permanent private halls
The Universities Tests Act 1871 opened all university degrees and positions to men who were not members of the Church of England (subject to safeguards for religious instruction and worship), which made it possible for Catholics and Non-conformists to open private halls. The first Catholic private halls were Clarke's Hall (now Campion Hall), opened by the Jesuit Order in 1896 and Hunter Blair's Hall (later St Benet's Hall) opened by the Benedictine Order in 1899.
In 1918 the university passed a statute to allow private halls which were not run for profit to become permanent private halls and the two halls took their current names.
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