In the Arrowood books, the narrator Norman Barnett often uses the terms ‘nob’ or ‘toff’ when talking about people of a high status. These terms were common in the 19th century, and are still used in the UK today.
I’d never wondered where the terms came from until I heard a BBC Radio 4 programme Start the Week on the history of India. During the discussion, the historian William Dalrymple said that the term ‘nob’ came from the term ‘nawab’ (a governor of the Mogul Empire), from which came the 17th century term ‘nabob’ (a person who came back to Britain after becoming wealthy in India).
There are other theories as to the origin. The OED, which defines nob as ‘a person of some wealth of social distinction’ isn’t sure. It was in use as early as 1676, and might be an abbreviation of ’noble’ or ’nobleman’, or it might come from ‘nab’ meaning the head, a hat, or a coxcomb. wiktionary suggests it might come from ‘white-nob’ (“white-head”), a term for the white, powdered wigs worn by middle class people in the 1700s.
‘Toff’ is defined by the OED as ‘a person who is stylishly dressed or who has a smart appearance; a swell; (hence) one of the well-to-do, a ‘nob’.’ This source says it might derive from the 18th century ‘tuft’ (a titled student at Oxford who wore a gold tassel on their cap, also called a ‘tuft’).
So, there you go.