Death of a Selachii
The City Watch are the police force in Ankh Morpork charged with upholding the law and keeping the peace. Policing in the city was once carried out by four different groups, The Night Watch, The Day Watch, The Palace Guard and The Cable Street Particulars. These were merged to become the Ankh Morpork City Watch lead by Sir Sam Vimes former Captain of The Night Watch now Watch Commander.
Sir Sam Vimes' belief in equality and justice has reformed the Watch from a group of corrupt and lazy ne'er-do-wells into an effective and trusted force for good. Many of the police forces in other cities on the Discworld have at least one officer who trained in Ankh Morpork and watch officers are now colloquially referred to as Sammies.