Totally off topic, but I always came to my mind when I heard it and everybody keeps on asking “Cardigan like the sweater?” when I say where I’ve been. In fact I always say Aberteifi now. 
But still curious if it’s related, and the only story I found talks about James Brudenell, 7th Earl of Cardigan. But he’s English, and only English places are mentioned so I can’t understand if it’s the same or there’s another one in England?
Also, I remember @rich mentioning going to a meet-up in Leeds, at some point - and that had reminded me I’ve been there once (for a series of coincidences)…at the Brudenell Social Club! 
This guy’s a recurring presence!