The College of Saint John the Evangelist. Named after The Hospital of Saint John the Evangelist. Founded 1511 by Lady Margaret Beaufort. Sister Colleges – Balliol College Oxford and Trinity College Dublin. Men and Women – Undergraduates 569 Postgraduates 337. St John’s is the third largest college in the University of Cambridge. It sits on a huge site, straddling the River Cam a little to the north of the city centre, which is within walking distance. Its closest neighbours are Trinity and Magdalene