The Main characters in the Watch are:

Sir Samuel Vimes, Carrot Ironfoundersson, Angua Von Uberwald, Frederick Colon, Cecil Wormsborough St. John Nobbs (Nobby), Detritus

Sir Samuel Vimes

Samuel Vimes was first seen lying in a gutter at the start of Guards! Guards!. Since his first appearance, Sam Vimes's fortunes have changed dramatically. He started out a lonely drunkard, in charge of a Watch that most people pretended didn't exist. Now he is married to the richest woman in Ankh-Morpork, holds a position of influence in the city, and has just been proclaimed a Duke by the Patrician. Despite despising dwarfs, trolls, Assassins, monarchy, the Patrician and the undead, Vimes is generally fair in his policing - and he always gets his man, woman or golem, even if it sometimes takes a while. He is respected by all the Watchmen, and has a rare talent for upsetting important people, which is perhaps why Vetinari likes him so much.

Carrot Ironfoundersson

Captain Carrot Ironfoundersson is technically a dwarf, apart from the small fact of being nearly two metres tall. He was adopted by dwarfs when he was found near their mine as a small child, and was sent to the Ankh-Morpork Watch to have a Man made of him. In that respect, it was certainly a success. He is also quite probably the King of Ankh - he has an old sword, a birthmark shaped like a crown, and heaps of charisma. It has been hinted, however, that he may have disposed of any written evidence to that fact - perhaps a King who is truly good is the scariest ruler of all. That aside, he is honest, kind, caring, incredibly simple whilst also being very intelligent, and has an incredible memory for names. Everyone knows Captain Carrot, everyone likes Captain Carrot, and everyone respects Captain Carrot. That and the fact that his girlfriend is a werewolf means that he can do pretty well what he likes - but he's just too nice for that. It would be very annoying, if the man wasn't so likable.

Angua Von Uberwald

Angua von Uberwald is a werewolf, and was recruited as a result of the 'affirmative action hiring procedure' started by Lord Vetinari after it looked as if the Watch was getting too popular, along with Detritus and Cuddy. She has since formed what the Discworld Companion calls a 'liaison' with Captain Carrot and gets on reasonably well with everyone else, and is particularly good friends with Corporal Littlebottom

Frederick Colon

Frederick Colon has been a member of the City Watch for nearly thirty years. He is aged around sixty, and had been intending to retire to the country, but never really got round to it. He has probably been in the Watch longer than anyone else; he is also the only one to never really adapt to its changing nature, and often thinks of the days when it was just him, Nobby and Captain Vimes. It is reasonable to suspect that he was also the Sergeant mentioned in The Colour of Magic.

Cecil Wormsborough St. John Nobbs (Nobby)

Cecil Wormsborough St. John Nobbs is probably human. He was the third original member of the Watch at the start of Guards! Guards!, and has adapted well to the changing nature of the Watch. He is a man of many parts - he does folk dancing, and is a member of the Peeled Nuts (Ankh-Morpork Civil War Reconstruction Society). Apart from that, he's just Nobby, and thats all that can be said.

Detritus

Detritus was recruited to represent an ethnic minority in the Watch, along with Cuddy and Angua. He has since risen up the ranks with the speed of Captain Carrot, becoming a Sergeant in two years. He has an unusual approach to questioning, usually along the lines of, "It was you what done it wasn't it, own up," and can go on patiently asking for hours until the questionee gives in. The only thing that will defeat him is an outright denial. Detritus has shown himself to be a trustworthy officer, and can be quite intelligent, particularly when the temperature is below five degrees.

from left to right: Nobbs, Carrot, Vimes, Colon