Corvinus Gaunt

Corvinus Gaunt (fl. 18th century) was a wizard, and a member of the pure-blood House of Gaunt. As such, he was one of the direct descendants of Salazar Slytherin and was a Parselmouth, as well as being presumably very inbred and rich. Gaunt knew about the Chamber of Secrets, and he was instrumental in keeping the entrance to the Chamber a secret.

In the 1700s, there was a proposal to install an elaborate plumbing system at Hogwarts Castle. This, of course, threatened the secrecy around the entrance to the Chamber of Secrets which, at the time, still had its original appearance — a concealed trapdoor and a series of magical tunnels — and which was located on the site where a girls' bathroom would be set up.

Corvinus Gaunt was, at the time, a student at Hogwarts and, as a descendant of Salazar Slytherin himself, knew where the entrance to the Chamber was and how to open it. Corvinus was responsible for secretly protecting the entrance, having concealed it behind plumbing fixtures and a sink (which today are part of Moaning Myrtle's Bathroom), so that those who knew how could still access the Chamber.

Corvinus may have been one of the last rich Gaunts, before the inbreeding - which would have plagued him too - and the love of grandeur squandered the money.

Etymology

 * "Corvinus" is the diminutive of "Corvus", which derives from Latin corvus, "raven". was a 15th-century Hungarian king, possibly referring to Corvinus' status as a pure-blood, as many pure-bloods consider themselves akin to royalty. Also,  was a Roman general, author and patron of literature and art.
 * The word gaunt is defined as "haggard, drawn and emaciated" and "bleak, desolate".

Behind the scenes

 * As a member of the House of Gaunt, Corninus presumably owned Salazar Slytherin's Locket, and possibly owned Marvolo Gaunt's Ring, assuming the latter had passed into the family's possession by this time.

Appearances

 * Pottermore