When they were founded, the famous and prestigious British universities of Oxford and Cambridge were open only to Anglicans (also known as adherents of the Church of England). Catholics, Quakers, other non-conforming Christians, and Jews (let alone avowed atheists) were not welcome.
|Oxford Museum of Natural History|
Actually, it is not so simple. Apparently the law required students to sign “39 Articles” of agreement with particular Anglican dogma; those who were unwilling to sign were not awarded diplomas. Also, the universities had rules about non-adherents being employed as professors or university officers, or being awarded fellowships, and students and staff were required to attend Anglican religious services.
Even some people who belonged to the Church of England weren't able to earn diplomas in the school because they didn't agree with all 39 statements and wouldn't “sell out” their beliefs by pretending they did. The artist William Morris is in this category.
On this date in 1871, Parliament passed the Universities Test Act, thereby opening the universities to all who were academically qualified, regardless of religion or lack of religion. The act also abolished the rule of mandatory worship for students and staff.
Many see this act as a great advancement in freedom of religion.