Hello
As you probably already know by now

Henry Knevett was the son of John Knevett, Grazier of Gasthorpe Norfolk (from his Cantab Alum listing).
He was born 1 Mar 1742, went to Bury Grammar School in Suffolk then to Cambridge.
He was a vicar (of various types) in Suffolk and died on 30 Dec 1822.
I think that he and Elizabeth had at least 11 children, and have traced a couple of them for several subsequent generations.
Sadly, whilst there are several direct descendants trying to trace his ancestors, I don't know of anyone who has got any more information about John of Gasthorpe (or anyone earlier).
Knev