John Saltmarsh was born on 7 May 1908, the son of Winnifred and H.A. Saltmarsh. He grew up in Oakington, five miles northwest of Cambridge, where his father farmed 400 acres. He was educated at Gresham's school, Holt, and won a major scholarship to King's College, Cambridge at 17. There he was tutored in economic history by John Clapham and started to become absorbed in the history and architecture of King's. He was awarded a first in the historical tripos at the end of his undergraduate career, and was elected to a Fellowship at King's two years later, at the age of 22, having submitted a dissertation on the college's estates. He became a full lecturer for King's College and Cambridge University in 1937 and was appointed the College Librarian. At the same time, he embarked upon a six volume work, 'King's College Memorials', with college backing; the work was abandoned, however, with the start of the war, when Saltmarsh was recruited to work at Bletchley Park. Soon after his return to the college, Saltmarsh was relieved of his post as Librarian, but was appointed, in turn, the college's first archivist. He simultaneously began his 23 year tenure as the college's director of studies in history. In the years that followed, he was Vice-Provost (1955-61), lectured in economic history for the university, gave numerous public lectures on King's College, its chapel, Tudor Cambridge and Tudor Cambridgeshire, and published widely on the same subjects. His history of King's College, published in the 'Victoria County History of Cambridgeshire' (vol. 3, 1958), continues to be the best study ever written on the history of the institution and his 'Plague and economic decline in the later middle ages' was not without influence. John Saltmarsh retired from college teaching in 1971, and first fell seriously ill in 1972. Although he made a good recovery from his first illness, he was not so fortunate when he fell ill again and Saltmarsh died on 25 September 1974 at the age of 66.