You might want to read more about the multicultural influences that shaped England. The Roman invasion, for instance. Or after the Norman invasion, the ruling class who were living in Oxford and writing and speaking in French.
Oxford University in particular was very much a site for international scholarship from when it began in the late 11th century to the present day. The history of Oxford has always been international and multicultural.
Oxford is also closely linked to the history of colonialism and empire. In the words of the cultural historian Stuart Hall, 'We are here, because you were there.'
I recommend David Olusoga's book Black and British.
The idea that Oxford's 'historic heritage' is exclusively English is a myth. At the risk of outing myself, I'm a medievalist who teaches in Oxford.