The life of the college was disrupted by the English Civil War. Leoline Jenkins, who became principal after the war in 1661, put the college on a more stable financial footing. Little happened at the college during the 18th century, and the 19th century saw a decline in numbers and academic standards. Reforms of Oxford University after two Royal Commissions in the latter half of the 19th century led to removal of many of the restrictions placed on the college's fellowships and scholarships, such that the college ceased to be predominantly full of Welsh students and academics. Students' academic achievements rose in the early 20th century as fellows were appointed to teach in new subjects. Women were first admitted in 1974 and now form a large part of the undergraduate population.
There are about 475 students at any one time; the Principal of the college is Sir Nigel Shadbolt. Former students include Harold Wilson (who was twice British Prime Minister), Norman Washington Manley (Chief Minister of Jamaica), T. E. Lawrence ("Lawrence of Arabia"), Angus Buchanan (winner of the Victoria Cross), and Viscount Sankey (Lord Chancellor). The university's professorship of Celtic is attached to the college, a post held by scholars such as Sir John Rhys, Ellis Evans and Thomas Charles-Edwards. Past or present fellows of the college include the historians Sir Goronwy Edwards and Niall Ferguson, the philosopher Galen Strawson, and the political philosopher John Gray.
Jesus College was founded on 27 June 1571, when Elizabeth I issued a royal charter. It was the first Protestant college to be founded at the university, and it is the only Oxford college to date from Elizabeth's reign. It was the first new Oxford college since 1555, in the reign of Queen Mary, when Trinity College and St John's College were founded as Roman Catholic colleges. The foundation charter named a principal (David Lewis), eight fellows, eight scholars, and eight commissioners to draw up the statutes for the college. The commissioners included Hugh Price, who had petitioned the queen to found a college at Oxford "that he might bestow his estate of the maintenance of certain scholars of Wales to be trained up in good letters." The college was originally intended primarily for the education of clergy. The particular intention was to satisfy a need for dedicated, learned clergy to promote the Elizabethan Religious Settlement in the parishes of England, Ireland and Wales. The college has since broadened the range of subjects offered, beginning with the inclusion of medicine and law, and now offers almost the full range of subjects taught at the university. The letters patent issued by Elizabeth I made it clear that the education of a priest in the 16th century included more than just theology, however:
...to the Glory of God Almighty and Omnipotent, and for the spread and maintenance of the Christian religion in its sincere form, for the eradication of errors and heresies, for the increase and perpetuation of true loyalty, for the extension of good literature of every sort, for the knowledge of languages, for the education of youth in loyalty, morality, and methodical learning, for the relief of poverty and distress, and lastly for the benefit and well-being of the Church of Christ in our realms, we have decreed that a College of learning in the sciences, philosophy, humane pursuits, knowledge of the Hebrew, Greek and Latin languages, to the ultimate profession of Sacred Theology, to last for all time to come, be created, founded, built, and established....
Price continued to be closely involved with the college after its foundation. On the strength of a promised legacy, worth £60 a year on his death (approximately £15,300 in present-day terms), he requested and received the authority to appoint the new college's principal, fellows and scholars. He financed early building work in the college's front quadrangle, but on his death in 1574 it transpired that the college received only a lump sum of around £600 (approximately £153,000 in present-day terms). Problems with his bequest meant that it was not received in full for about 25 years. As the college had no other donors at this time, "for many years the college had buildings but no revenue".