In the Discworld novels of Terry Pratchett, the Archchancellor is the head of Unseen University, the Disc's premier college of magic, situated in Ankh-Morpork.
The Archchancellor is described as being the head of all magic in the same way the Queen is the head of the Commonwealth. That is, he has a lot of potential power but little actual power.
Nevertheless, the Archchancellor is considered an important figure and holds a seat on the Ankh-Morpork council (although this council itself has no power either). He is a sort of magical adviser to the Patrician of Ankh-Morpork as well.
The Archchancellor is elected on the Eve of Small Gods. Well, not exactly elected, because wizards don't have any truck with the undignified business of voting, and it is well known that Archchancellors are selected by the gods (which wizards don't believe in). The double doors to the Great Hall are locked and triple-barred. An incoming Archchancellor has to request entry three times before they will be unlocked, signifying that he is appointed with the consent of wizardry in general. This process seems to satirise the election of the Pope.
In more recent times, the lifespan of Archchancellors has been seen to be a bit on the short side, as wizardry's natural ambition took its toll. Unseen University has been in existence for thousands of years, and the average Archancellor remains in office for about eleven months.
Unseen University has had many different kinds of Archchancellor over the years - big ones, small ones, cunning ones, slightly insane ones, extremely insane ones - they've come, they've served (in some cases not long enough for anyone to complete their official portrait) and they've died. The senior wizard in a world of magic has the same prospects of long-term employment as a pogo-stick tester in a minefield.
It should be noted that Mustrum Ridcully, incumbent Archchancellor at the time of the last Discworld novel, Going Postal, seems to have had a very successful and above all, injury free career as Archchancellor. This might possibly have something to do with his habit of springing up behind would-be assassins, shouting loudly at them and banging their head repeatedly in the door.
There is also an Archchancellor at Bugarup University on the continent of Fourecks. At last account, this was Bill Rincewind . When the two Archchancellors met, Ridcully was careful to refer to his counterpart without the capital - as 'archchancellor'.
List of former Archchancellors (referenced in Discworld canon):
- William Badger
- Bewdley
- Buckleby
- Ezrolith Churn (very old, Archchancellor in Eric)
- Cutangle (Archchancellor in Equal Rites.)
- 'Trouter' Hopkins
- Scrawn
- Greyhald 'Tudgy' Spold (tried to hide from Death by sealing himself in a box which nothing could enter, including oxygen. Last words heard: DARK IN HERE, ISN'T IT? Succeeded by Galder Weatherwax)
- Ymper Trymon (305th Archchancellor, in The Light Fantastic
- Virrid Wayzygoose (Archchancellor-elect; killed by Coin the Sourcerer before he was invested.)
- Galder Weatherwax (304th, went mad with power in The Light Fantastic. Distant relative of Esmerelda Weatherwax .
