The fragility of Edwardian Protestantism was revealed in the speed of its dismantling. The death of the young king on 6 July 1553 prompted a succession struggle between the supporters of Mary Tudor and of Lady Jane Grey that was felt deeply in Cambridge. Choosing sides in this contest was a fraught matter and Edwin Sandys, Cambridge's vice-chancellor in the summer of 1553, was among those who found themselves stuck on the wrong side, implicated in a failed attempt to block Mary's path to the throne. Sandys dined with Northumberland upon his arrival in Cambridge, and the next day preached a sermon in support of Queen Jane that pleased the duke sufficiently that he ordered it to be printed. Sandys had just finished preparing his text when the news came: Northumberland had surrendered. This brought disaster to both men.

According to the account offered by John Foxe – a narrative which it has been suggested was procured from Sandys himself – some of the university seniors turned upon Sandys with striking rapidity, declaring that he be stripped of ‘the statute booke of the Universitie, the keys, and such other things that were in his keepyng’: the trappings of his office. When Sandys attempted to take his usual place at a university congregation the following day, what Foxe called ‘a rabble of unlearned Papists’ tried to unseat him. In the ensuing struggle Sandys pulled a knife before friends persuaded him to bear this indignity more stoically. The men of Cambridge were, in this account, literally at each other's throats as the Edwardian regime's attempts to perpetuate itself crumbled. Allegiances seemed to shift quickly; Foxe sneered that William Mowse, the Master of Trinity Hall, and one of those who were sent to seize the statute book from Sandys, ‘beyng an earnest Protestant the day before … now was he become a Papist’. This, of course, was Elizabethan polemic, not Mowse's own understanding of his part in these events. The choice between Mary and Jane took in much more than religious identity: and support for the former cannot be read as anti-evangelical reaction. Yet the role of Mowse, an Edwardian appointee, and the other ‘rabble’ points to a wider truth: the seeds for the rapid re-establishment of Catholicism in Cambridge under Mary could be found, in part, within the Edwardian university.