1749, Henry Fielding, Tom Jones, Folio Society 1973, p. 443:they now shook hands heartily, and drank bumpers of strong beer to healths which we think proper to bury in oblivion.
1859, Dickens, A tale of two cities,Sydney Carton drank the punch at a great rate; drank it by bumpers, looking at his friend.
(colloquial) Anything large or successful (now usually attributively).