“Domesday Book has Difgelibi ‘Dufgalls Place’, according to Morris a norse name from Old Irish Dubhgall meaning ‘black foreigner’ and used in Ireland of Norwegian raiders who terrified coast dwellers”.
Yorkshire Placenames.
Peter Wright
Dalesman Publishing 2001
I'd take issue with Morris there, Fitz. The Norse in Ireland were referred to as Finn Gael - 'white foreigner' (the origin of Fingal's Cave). Dubh Gael - 'black foreigner' - was applied to Danes.
This particular Dubhgall may have arrived here during Halfdan's 'great settlement' of East Yorkshire in 876 a.d.