Who Built this Hotel?

I was visiting Europe and decided i would make it my business to find out more about my great-uncle, a London solicitor, who I had strangely never heard any mention of by anyone in my father's family. I spent long hours poring over computer records and confirmed the names of his wife and children shortly before travelling to London (this was not easy for various reasons). The second weekend I was in London my relatives took me to a hotel they love in rural South Wales which they have been visiting regularly for several years. We had already discovered coincidentally that the hotel (built as a country house) was a beautiful half hour walk on foot from a house previously owned by another part of our family, but this was with my mother's family and not even remotely connected to my father's family. While my relatives enjoyed the River Usk, I spent an afternoon reading books in the hotel library and discovered the building we were in had been built by - wait for it - the father of my long lost great-uncle's bride. The family had lost their money shortly after my great uncle married into the family and it had been put up for sale, eventually being turned into a hotel. Strange.