The Earls of Carnarvon is a good example, the family name is Herbert and they were from South Wales originally and became Earls of Pembroke. When a younger son inherited lands through the female line in Hampshire, (Highclere aka Downton Abbey) he chose a Welsh title as to hark back to that ancestry despite the fact that he no any of his ancestors had ever had anything to do with Carnarvon which is in North Wales.
Basically any British title post about 1400 probably has nothing to do with the lands held by the family. e.g. the House of York mostly had lands in the Welsh Marches. There are exceptions (Earls and Dukes of Northumberland) but they are the exception rather than the rule.