A few years ago I did a crash course in English history from Julius Caesar to James I (and VI), and for an awful lot of that period Northumbria was different. I seem to remember that Northumbria was the last bit of Anglo-Saxon England to unite with the rest - and even after the Conquest it was something of a kingdom-within-a-kingdom for quite some time, reporting to London but only as often as absolutely necessary. I thought that explained a lot.

Pip
who once played Elsie Marley at quite a reasonable speed
(but only once)