Which preposition to use with northumbrian

of Occurrences 2%

The Mitfords of Mitford can boast, if ever family could, of being Northumbrian of the Northumbrians, as they were seated here before the days of the Conqueror, who made such a general upsetting amongst the Saxon landowners.

than Occurrences 1%

" The next division may be termed semi-historical; that is, they treat of events which actually happened, but which have chiefly a local interest; and these may therefore be said to be more truly Northumbrian than any others.

Which preposition to use with  northumbrian