Sidney Sussex was founded on Valentine’s Day, 1596, by the legacy of Lady Frances Sidney, Countess of Sussex. She served as a Lady in Waiting to Elizabeth I and bequeathed £5,000 plus silver plate on her deathbed to create “some good and godlie moniment for the mainteynance of good learninge”.
 
The college’s most famous early student was Oliver Cromwell, who joined shortly after the college’s founding. Though he never graduated (his father became ill), Cromwell’s presence made Sidney Sussex politically significant during the English Civil War. 
 
Sidney Sussex has an extraordinary link to the 1605 Gunpowder Plot:
Lord Harington of Exton, the college’s founder, helped Princess Elizabeth (nine-year-old daughter of James I) escape to safety before Gunpowder Plot conspirators could kidnap her. After the plot failed, another Sidney benefactor, Edward Montagu of Boughton, put forward the bill that created Bonfire Night (the public celebration marking the plot’s failure).
 
Interesting fact...
Oliver Cromwell’s head is buried beneath the college chapel. Only the Masters of the College know the exact location of the burial.