Vetinari
Patrician, the (Lord Havelock Vetinari). Age
uncertain. Background unavailable. Reputedly trained at the ASSASSINS' GUILD school.
Now supreme ruler of the city of Ankh-Morpork, to which he is totally devoted. Tall, thin,
and generally to be seen wearing black.
He is the most recent of a line of unelected heads (see below). As their names suggest, these were not wholly pleasant or well-balanced men and soon met their ends, as did a red-hot poker in the case of one particularly unpopular ruler. Lord Vetinari, on the other hand, is very, very sane. And still alive.
Past Patricians have included:
Hargarth, Frenzied Earl
Harmoni, Deranged Lord
Nersch the Lunatic
Olaf Quimby II
Scapula, Laughing Lord
Smince, Lord
Snapcase Mad/Psychoneurotic Lord
Winder, Homicidal Lord
He appears to have survived by being equally distrusted and disliked by all interest groups in the city but also by carefully not being as unpopular as every interest group is to all the others.
A popular form of punishment and mass entertainment in the reign of Mad Lord Snapcase was the tearing to pieces of criminals by teams of wild horses. Lord Vetinari appeared to be like the man in the middle of the arena who had managed somehow to chain all the wild horses to one another and is groaning theatrically while watching them drag one another to their knees. The result, in political terms, is stability achieved by equal tension in all directions.
His genius lies in the realization that everyone craves stability even more than they hunger after justice or truth. Even revolutionary anarchists want stability, so that they have breathing space to fight their real enemies, i.e., those higher than themselves in the revolutionary anarchist council, and those heretics whose definition of revolutionary anarchy differs from their own by about half a sentence in paragraph 97 of the charter.
This policy is dimly perceived by the more intelligent Guild leaders in the city. Yet when an assassination attempt was made (Men At Arms), the ASSASSINS' GUILD themselves were prominent in the search for the perpetrator. Annoying as the Patrician is, it is so easy to think of someone worse. Technically, Vetinari seems to have given in to every demand of every Guild for years, so the Guilds are driving themselves mad wondering why he is therefore still in charge.
It has been remarked that if the Patrician were thrown to a pack of wolves he would, after chatting to them for a few minutes, have them tearing one another to shreds. It is certainly the case that when he was thrown into one of his own rat-infested, scorpion-filled dungeons he organized the rats to eat the scorpions. and then to bring him food and reading matter. He'd also, years before, secreted a key to the dungeon behind a secret slab. As he wrote in his unpublished MS entitled The Servant, a sort of handbook for the politically ambitious: 'Never build a dungeon that you cannot get out of'
He is entirely without vices in any normal sense of the word. If he had any, we can be sure some Guild or other would have made use of them by now.
It is true that he has banned street theatre and hangs mime artists upside down in a
scorpion pit opposite a sign that says 'Learn The Words', but this may be considered an
excusable peccadillo or possibly an amusing character trait. He does have a small and very
old terrier, called Wuffles, to which he is said to be quite attached (although it has not
been seen in recent volumes and presumably even despotic rulers have a sad patch of earth
behind the toolshed). 
Probably his greatest enemy is Captain (later Commander) VIMES of the City WATCH but, strangely, the person with whom he gets on best - or least badly - is Corporal (later Captain) CARROT Ironfoundersson of the same Watch. They share the same obsessive interest in the city itself
Lord Vetinari lives in what was once the royal family's Winter Palace in Morpork (the summer palace is a long way from the city, and the reason will easily be appreciated by anyone who has spent a summer near the river). He manages the city either from a wooden seat at the foot of the steps on which is the ancient golden throne of the city, or more usually from the Oblong Office, high in the palace.
This is where he gathers information. People tell him things, for all sorts of reasons. He has a bedroom. He presumably sleeps.
The Patrician has expressed a wish that, one day, he could retire and cultivate a garden. It will probably never happen. It is impossible to imagine him as a mere civilian. But if he did indeed take up horticulture, the roses would grow in lines, the garden would bloom on command - and the slugs would eat the caterpillars.