Lord Vetinari
In the first book called The Colour of Magic, Rincewind is arrested by a character called the Patrician, ruler of Ankh-Morpork who tells him that he will kill him for counterfeiting unless Rincewind becomes a tour guide for the character Twoflower. The Patrician later hires assassins to murder Twoflower after being asked to do that by the leader of Twoflower’s home country. The Patrician isn’t given a name by the book.