Oxford is a city of England in Oxfordshire.
In the Sherlock Holmes stories
The University of Oxford (informally Oxford University or simply Oxford) is a collegiate research university located in Oxford, England. While having no known date of foundation, there is evidence of teaching as far back as 1096, making it the oldest university in the English-speaking world, and the world's second-oldest surviving university. It grew rapidly from 1167 when Henry II banned English students from attending the University of Paris. After disputes between students and Oxford townsfolk in 1209, some academics fled northeast to Cambridge, where they established what became the University of Cambridge. The two "ancient universities" are frequently jointly referred to as "Oxbridge". (wikipedia)