There was also a special released for the Millennium, "Black Adder Back and Forth". Basic plotline:

Edmund is having a party for the Millennium, to which the usual Black Adder posse is invited. During the course of the meal, Edmund claims he has invented a time machine, and wagers £10,000 that he can retrieve any item from any period of time for any of the guests. The bet made, he enters his 'time machine' - which, deviously, has a secret trapdoor leading to his basement, which is full of old, antiquated junk. However, Baldric has built the time machine from plans by Leonardo Da Vinci, and it actually works. WACKY HIJINXS ENSUE as the duo travel to various points in time, rather predictably screwing up history.

Very enjoyable, and certainly full of dark humour, but like so many remakes I found it not quite up to the standards set by the rest of the series. Perhaps some things are best left alone.