Corrected entry: In the episode "Beer", set in the 1560s, the "Happy Birthday" song is sung by several characters. This song was not written until 1893 by two American school teachers, copyrighted in 1935. Neither is the song in the public domain. It still earns significant fees to the copyright holders each time it is recorded for sale, i.e. in a movie or on television. In most of the episodes, the various historical inaccuracies are intentional. This one, though, appears to have been an accident, a genuine mistake on the part of the writers. It should be noted that unintentional historical errors are very rare in Blackadder, "unintentional" being the key word.
tromatic
10th May 2003
Blackadder (1986)
4th Jul 2003
Blackadder (1986)
Corrected entry: In the first series the lead character's name was written as two words, "The Black Adder" (well, technically three words), and in subsequent series it was written as one word, "Blackadder". This is not a mistake, however; this is the normal way that languages evolve. The name evolved from the two word pseudonym used by Prince Edmund into the one word name used by his descendants.
Correction: This is not valid trivia. It's obvious to anyone who watches the show, or even just reads the title.
Correction: There is no way this mistake could have been overlooked in the production process. For starters the producers would have had to pay the royalties. This is entirely a deliberate gag by the writers.