That was a hell of a generic question and since there are too many cities in Tibia and the forum has a limit of characters allowed on answer, I tried my best to summarize the main points of each city. Still I needed to crack the answer into a post and comments, so I could enter all data.
If in the future someone wants to know more about one specific city, I'll be glad to develop more of it. Took a lot of job to research all this information and unify it, so I really hope you'll all enjoy!
1 - Thais
Thais is one of the oldest cities in Tibia, ruled by King Tibianus III and capital of the Kingdom of Thais (which has other settlements like Fibula, Greenshore, Venore, Edron, Stonehome, Cormaya, Liberty Bay along with the other Vandura islands, Port Hope, Rookgaard, Isle of Destiny, Meluna and Travora.
The name of the city is given after a legendary warrior who founded the settlement. The original name was Tradespot and it was built to be a place to humans that wanted to avoid the orc attacks. Thais (the warrior) was a charismatic leader who united an army and developed the settlement. As Tradespot flourished, it attracted more and more people, becoming an important city, both to commerce and protection.
After Thais died (during an orc raid) his son assumed the crown and announced Thais as the capital of the continent. Also Tibianus I developed the cultural life in the city. One of Tibianus I successor was King Xenom, who wanted to build a new model city for the rich people. That was the origin of Carlin;
2 - Carlin
Carlin is a town entirely ruled by women. Their queen is Queen Eloise and the city is in an endless rivalry with Thais since its early days. Originally planned to be a Thaian colony, Carlin struggled with several orc raids, being a land where almost no one wanted to go to.
Not wanting to accept the failure, King Xenom started to send his soreheads (e.g. nobles and free thinkers who did not agree with his politics) to Carlin. Because of that, the city grown divided in two large groups: one made of people who did not like the Thaian Kingdom (the druids that originally lived nearby and the people sent to the exile) and one that was commanded directly by the King (the Governor and the Red Legion).
Since the orc raids continued to run and the men were always in need, the food supplies and other minor services were given to the druids to manage. As they got more and more powerful, they decided to pass some of their knowledge to the women of the town, who got more and more dependable as time passed by.
One of the most notorious exiled was the King's sister, Elorana. She acted to undermine Xenom influence as soon as she set foot on Carlin. When the Red Legion suffered several losses after a big battle with the orcs, the King had no choice but to order the retreat of his troops. After that, Elorana declared herself the Queen of Carlin and a female kingdom was established. Because of the strife with Thais, Carlin started a secret service called C.G.B. in order to spy and counterspy their rivals, in order to maintain the cities independence.
3 - Svargrond
Svargrond is the Northern city, a large human settlement in Hrodmir, built to be a small trading post from Carlin as well as an ore depot. Although there already was a native civilization living in Hrdomir, the barbarians (as they were called) had a nomadic lifestyle and thus did not occupy any place at all.
Soon some of the barbarian got interested in the settlement and started living altogether with the Carliners. The rest continued to live their nomad way of life and saw those inventions with lots of suspicions. The commerce soon started to develop the settlement before a sea serpent plague made the routes from Carlin to Svargrond impossible to pass safely.
A few decades passed until the route was again re-established and in between the barbarians divided themselves on the ones who firmly set foot on the settlement and maintained Svargrond and those who continued or went back to the nomad life.
Svargrond is currently ruled by their jarl, Sven the Younger. His reign only exists due to people's satisfaction, thus he is responsible for the city to prosper and civilize. Due to the old relations with Carlin, their relationship is quite peaceful, although Svargrond is independent and Carlin exerts little to no influence at all.
Even though the city is quite peaceful, the surroundings are full of Hrodmir dangers. From the cultists on deeper Formorgar Mines to the Frost Dragons and Chakoyas, every explorer must be aware that a misstep can be fatal.
4 - Venore
Venore was also another Thaian colony settled to supply Thais. Initially designed to be a wood source, Venore grew in the marshy swamp. Convicts were sent to southern Venore as forced labourers to cut wood and help with building a cathedral there. Due to a massive earthquake, though, the site was destroyed and abandoned. The remained prisoners found an outlaw camp and populated the region.
After the discovery of spiceweed, Venore started to flourish, since its use on cooking brought many people to start trading there. The wealth brought by the constant trading activities made Venore's influence spurt. As the local administration was progressively changed to the hands of the merchants, Thais started to be dependent of Venore, and not vice-versa.
As many of the commerce on the old days were shady business, gambling, and booze selling were part of the successful case of Venore's wealth and status. Even though the city has enough power to gain independence from Thais, they'd rather pay some taxes than lose its influence on the great kingdom of Thais.
Since Thais is dependent of Venore, the administrators of the city does not like the independence status of Carlin. They are always trying to undermine that independence so they can acquire more and more influence. Because of that, a Venorean secret service (AMIN) is always trying to act behind the scene.
One of Venore's biggest schemes was the annexation of Liberty Bay. The wealthy merchants were eager to get their hands on the resources of Vandura. They forged an emergency situation, begging Thais for military assistance against rebels and anarchists. Thais did not have enough military resources to intervene, so Venore "generously" offered mercenary soldiers.
Once Liberty Bay was subdued, Thais stopped paying the mercenaries and some of them became pirates. Some of them even are recognized as members of the colonist resistance of Venore and still helps the city by plundering competitor's ships.
5 - Liberty Bay
Liberty Bay was originally named Summerhaven. Founded by pirates, its rich soil was the main reason it was known as a rich farm, from where sugar canes were abundantly grown. After the Thaian attack, the isle was subdued and got rebranded, named as Liberty Bay, both a believe and an irony. Many of the pirates, along with the mercenaries that were no longer paid, left to Meriana and Nargor, small islands nearby Liberty Bay.
Under the regimen of Percy Silverhand Liberty Bay lives a prosper life, though it deals with attacks of pirates, quaras and cultists quite a few times. The original members of Summerhaven that were not expelled are usually on bad conditions, living in the poor part of the town. Even though they seem to be resigned about their fate, you can still see they daydreaming about Summerhaven former glory.
We can find many little islands nearby Liberty Bay, including The Shattered Isles, in which Ferumbras himself built his citadel. After he was banned from this dimension, the citadel was isolated and remains seclude, at least until the time that he prepares for his return.
6 - Edron
Edron is a Thaian colony founded by seafarers during Tibianus III reign. When they discovered the crescent-shaped island, the Thaian Army was called to explore the region. General Benjamin led the troops into the north of the island, where they discovered ancient ruins fulfilled with dark secrets. Ferumbras also had interest on those secrets and soon a full open-battle started between the corrupted wizard and the king army.
Unfortunately to humanity itself, Ferumbras got the last laugh and Benjamin was the only survivor of that massacre. After that horror the man never was the same and today works as a postman with PTSD. This did not stop Tibianus, though, and soon the Sacred Order of the Knights of Banor's Blood arose on the island, providing its secure and under Sir Daniel Steelsoul's command, a picturesque town was built and named with the same name of the island: Edron.
To convince the mages that went with the settlers to stay in Edron, King Tibianus funded the building of the seven ivory towers and named it after his beloved poodle (yes, Noodles is a poodle): Noodles Academy of Modern Magic. The Academy soon got well known for its astounding new spells and wealth of knowledge. They even were able to exile Ferumbras in his citadel in Kharos.
After the establishment of Edron as an important colony, only a tragedy could affect its power. And so it did, when Kaine, the second-in-command officer, along with the priestess Agaltha, committed treason and fled with many enslaved labourers to the north of the isle, establishing a cult on the place nowadays called "The Hero Cave", as a remembrance of the fall of the former heroes.
Nowadays the city Edron finds peace on their grounds, protected by the legendary hero Avar Tar. The rest of the island, on the other hand, continues to be full of terrors like the ancient city of Cyclops, Cyclopolis, the dragon lair and the Hero Cave. Sometimes even Orshabaal (and his older brother) are sent to disturb Edron's peace and demands the union of young adventurers to make the demonic hordes retreat.
7 - Port Hope
Port Hope is the jungle city of the continent of Darama. Initially the settlement was built by a few sailors who shipwrecked when traveling from Venore to Thais. The stunning jungle around and the great mysteries made the city the base for hunters (represented by Grizzly Adams on Paw & Fur Society) and explorers (represented by Angus on The Explorer Society).
Though it is part of the Kingdom of Thais (therefore ruled by King Tibianus III), it does not have many attractions as other cities have. One interesting fact is that even though it is separated from the desert part of Darama, allegedly the jungle was the main biome of the whole continent, before the djinn wars.
8 - Ankrahmun
Ankrahmun is the southern city of the desert of Darama and its structure is dated from before the djinn wars. The city was built while Banor, the first human, was still alive and this great hero himself taught both the pharaoh and the citizens how to battle and how to fortify the city. The constant fights against undead and orcish armies made the people there to gladly accept sacrifices and embraced a culture to celebrate not only life, but death itself.
Only djinns still threatened the humans and soon a new hero neutralized the menace. Daraman, the prophet, taught Gabel about how humans and djinns could coexist in peace. The redemption of the Djinn king led to a civil war, in which the marids and Gabel allied with humans and the efreet and Malor allied with Drefia's necromancers.
Even though the human-Marid alliance was victorious, the price paid was high enough. As the fierce battle got to its decisive moments, the Efreet unleashed a cataclysmic firestorm, set the whole paradisical Kha'labal ablaze, turning the jungle into a barren wasteland. The actual pharaoh, Arkhotep, alongside with his councilmen, eventually all went to the dark side and betrayed the previously pharaoh, Arkhotep's father, turning Ankrahmun the land of the undead.
9 - Darashia
Darashia's story mix with Daraman's story itself, since it was founded by disciples of the holy prophet. By following their leader, they gave up all material belongings and created a humble, yet cozy, city. Built on the surroundings of an oasis, Darashia's is ruled today by Kazzan, from the Gadral family.
Even though the city itself doesn't have much to explore, the Devourer (name of the northern portion of desert of Darama) is full of dangers. From the dark pyramid, on north, to Drefia, on west, the undead raise their army and dark experiments are conducted on rituals ancient enough to survive the old wars.
10 - Kazordoon
Kazordoon is one of the main cities of the dwarf kingdom. Originally from Beregar, the dwarves that were dissident of the old king found The Big Old One, a huge mountain amidst the main continent. This happened in The Age of Chaos, long before the human race was created. By carving the rock, the dwarves created a whole new town, built to refuge the 'lill ones from the dark menace that ruled supreme all over Tibia.
Their ability to mine and sculpt on rock made Kazordoon an impenetrable fortress and they finally could develop and prosper. They chose to be isolated from the outside world for a long, long time, but finally they now are opened to everyone who is civilized enough to admire their powerful empire.
Proud and self-sufficient, the dwarves do not usually require help from strangers, but sometimes you can prove yourself with some challenges. Friends of the dwarves, the gnomes live right under Kazordoon, on Gnomebase, where you can challenge yourself through the warzones.
11 - Farmine
Farmine is the new outpost of the dwarves, created on the rough continent of Zao. The settlement was established as a way of expanding their mining to another new mines. Even though Farmine is a dwarf settlement, the areas nearby are full of different tribes and in order to safely expand the settlement and be in peace, they are in constant tries of diplomacy with all the old residents of Zao. Since this settlement is pretty-new, we don't have much history to tell about it, and even the services as bank and supplies shop only appears after the player improves the dwarven relation with other tribes, as part of the expansion plan of Farmine.
12 - Ab'dendriel
Ab'dendriel is the city founded by the elves, an ancient race created to fight Urgith's undead legions. Not being strong enough to turn the tides of the fate, the surviving elves disbanded to preserve their lives. As they took different pathways, five castes were formed over time, but only three survived until today.
Of the three races that we still have enough intel about, the Cenath were the most experienced in magic and, full of fear from the wars ecloding all-along Tibia, they decided to secure themselves. By unleashing a powerful magic altogether, they were able to rip the valley they were into and move it to another dimension. There they were undisturbed and could enhance their magic powers over centuries.
Unfortunately the dimension they were into went unstable at some point and their valley was expelled back to this dimension, falling through the sky like a meteorite. Less than half Cenath survived and only after Deraisim (another caste) scouts found them, they were really safe.
The Deraisim lived those centuries as nomads, traveling from several minor settlements. Some of the families stayed in each one, while most of them constant traveled between the sites. As time passed by, one of the settlements eventually got larger and larger and, by adapting ideas and culture from other races, the biggest trade post eventually become the foundation of Ab'dendriel, specially after the Cenath were rescued.
The last of the three races joined Ab'dendriel not far after. The Kuridai took refuge initially on a volcanic site and adapted themselves along the centuries to survive on this rough environment. Even though they were skillful warriors, eventually the orcish attacks were too much for them to take care of and the survivors finally joined their brothers on Ab'dendriel.
The name Ab'dendriel comes from the word déndron, which means tree. That is not any coincidence. The elven city was built using the largest and lifeful trees of the northern main continent of Tibia. Nowadays those three castes can be seen in the city. While the Cenath usually live on the upper floor, the Deraisim prefer to scout the environment of the floor. The Kuridai decided to live underground, where they can hone their skills as craftsmen.
13 - Yalahar
Yalahar is an ancient city built by the Yalahari, an ancient race created to battle on the God Wars, long back then. Their race was so advanced and gifted that, at some point, they turned themselves against the gods, refusing to fight a war which was not theirs. So, abandoning the battlefield, they travelled to one of the northern islands, creating the city of Yalahar.
There they continued their search for knowledge and science. Their magical powers and weapons were so advanced that they could easily repel any attacks. Being safe and sound, they were able to dedicate full-time on their quest and while analyzing the very structure of the universe, they discovered that there was some sort of "missing piece", something that their calculations clearly proved to exist, but that they were not aware of what it was.
After that astonishing discovery, all their efforts turned to try discovering that part of the puzzle they did not comprehend. And that, certainly, was their downfall. On their quest to grasp the incomprehensible, some of the most brilliant minds approached a success and snapped insane. Eventually the civilization could make an approximation theory and found a place between reality and non-reality, a place that should not be. That place, though, was not void, but inhabited by one thing which our words could only feebly describe as an entity. Knowing the power of names, they gave it the name "Variphor".
That maneuver intended to gain power over that entity, but it backfired. Variphor was not only aware of his own existence, but also he knew about our universe. His subtle influence seemed to be responsible for many destructive events of the past. To give him a name was to feed him with substance of our universe, making him more capable of exerting his influence.
Desperate after understanding what they've done, the Yalahari tried to undo their actions, but it was far too late. Tainted with forbidden knowledge and unable to resist that influence, sister and brothers turned out against each other, almost wiping all of their own race. The few remaining Yalahari, understanding that they were doomed, decided to part from this world.
After their departure, the minions took care of Yalahar and tried to maintain their ideals. However the sudden power soon turned into vanity. Acting first as representatives of the Yalahari, as time passed by they pretended to be Yalahari themselves. Living in luxury but unable to maintain and repair the ancient devices, as the mechanisms ceased to function, Yalahar began to crumble. Nowadays only the inner city still shows its former glory, although it is today much more a city of splendor than a city of knowledge.