Veltrick I
The founder, patron and inspiration behind the very first Ankh-Morpork City Watch. Veltrick I set up the Watch with the intention of it becoming an efficient and loyal police force and militia. Unfortunately, he was assassinated by his son four days after the Watch was established, with the connivance of the then-Empress of Sto, and the new monarch set aside his father's plan for efficient police.
The only things that survived the brief reign of Veltrick I are the continued physical existance of the Watch, and, crucially, a handful of the original issue of Watch badges. Most are in various City museums and it is believed the only original watch badge still active today is no. 177 - held in the Vimes family, the current holder being Sir Samuel Vimes, Commander of the Watch and Duke of Ankh.
Annotations
The establishment of the Watch by a head of state who was immediately assassinated parallels the Roundworld history of the U.S. Secret Service, founded by President Lincoln on April 14, 1865, the very day of his death. (Not their fault; initially, their duties were concerned solely with apprehending counterfeiters, not bodyguarding federal officials.)