FAQ

In both the books and the TV adaption the Headmaster's name was never given, though there was a scene in the second book where Dinah had to remove it from a list. In the TV series the headmaster is seen typing his name on a keyboard but it is not immediately clear what letters he is typing.

In the third TV series (Takes Over), the Headmaster's name was a plot point of the series. So the characters know but not the viewers/readers.

The first 3 episodes of Series 1 was an adaptation of the 1st book, the other 3 episodes were the 2nd book, The Prime Minister's Brain, Series 2 was adapted from the 4th book, The Demon Headmaster Strikes Again, and the third and last series was the 5th book, The Demon Headmaster Takes Over. The 3rd book, Revenge Of The Demon Headmaster (or Hunky Parker Is Watching You), and the 6th book, Facing The Demon Headmaster, were not adapted.