The Empire
The Empire is the largest and most powerful state in the Old World but with each of the provinces fiercely jealous of their autonomy it is as much a collection of states as a single country. Many a man or woman would think of themselves as a Middenlander or a Reiklander first and an Imperial citizen second. There are ten provinces (or eleven if one counts the Halfling Mootland which most humans deliberately don't!) Several of the largest cities including Altdorf, Middenheim, Nuln and Talabheim are also quasi-independent 'free cities' in their own right.
The current Emperor is Karl Franz I, the Elector Count of Reikland and Prince of Altdorf who took the throne twenty years years ago in I.C 2502.
Humans, Dwarfs, Halflings and Elves
Humans make up the overwhelming majority of the Empire's population but they are not the only inhabitants. Many tens of thousands of dwarfs also call the Empire home. Some are recent expatriates from the mountains, others are from families that have lived in Sigmar's land for generations. Dwarfs are stereotyped as hard workers, doughty soldiers and superb craftsmen, but also as greedy, miserly aggressive alcoholics.
Halflings are also a common sight in the Empire. Unlike the dwarfs they do have a homeland inside the Empire - the Mootland in Stirland. Halflings are, depending on who you ask, either charming, simple rustics or viciously cunning con-men and thieves who will rob you blind. Their appetite for food rivals the dwarf appetite for drink and gold.
Eves are very rare, very distrusted and few Imperials have even seen one in person. There are small but established elf communities in the major cities and it is rumoured an entire kingdom of them in the Laurelorn Forest of Nordland. All sorts of rumours swirl around these strange beings!
Foreigners
The Kingdom of Bretonnia to the South and West of the Empire is known for it's excellent wine, horrendous beer and food that is either divine or hideous depending on who one asks (expect to hear dark mutterings about frog legs and snails to come up whenever the topic is raised.) It is ruled by an aristocracy that is at once the most chivalrous in the world and so arrogant they make the average Imperial baron look like a Shallyan novice.
The Tzardom of Kislev to the East and North of the Empire is a perpetually frozen kingdom of bear worshipping warriors who regularly drink spirits of such strength they would give a dwarf pause. The Kislevites are famous for their excellent horsemen and are said to be ruled by a beautiful ice witch with strange and terrible powers.
Marienburg and the Wasteland to the West of the Empire was once part of Sigmar's realm proper but declared indepence a century ago. The great city port is famously rich and famously decadent where anything that can be bought or sold is and men from around the world and even (whisper it!)
Elves walk the streets.
There are other more distant lands but few Imperials know much of them.
The Gods
Sigmar Heldenhammer was the founder of the Empire and is now worshipped as it's patron deity having ascended to godhood. He is followed through out the Empire but his cult is most popular in the South and in Reikland.
Ulric, the god of Winter and wolves was the original main god of the pre-Sigmar tribes and is still more widely worshipped than Sigmar in the northern parts of the Empire with the city of Middenheim being the centre of his cult. Ulricans and Sigmarites have a fierce and occasionally violent rivalry.
Taal & Rhya the god of nature and the goddess of the harvest are generally worshipped together as husband and wife. Taal is sometimes seen as the 'king of the gods', and though widespread his cult is less powerful and far less politically active than either Sigmar or Ulric. The centre of the cult is in Talabecland.
Shallya is the goddess of healing and mercy. Though not particularly powerful and pacifist by nature her cult is perhaps the widely loved in the Empire.
Morr is the god of the dead and dreams. He is an enigmatic figure, but not a malevolent one and his cult are firm foes of the undead. The prime focus of Morr's priests and priestesses is overseeing the last rites of the deceased so that they enter the afterlife.
Verena is the goddess of law and learning and justice, the wife of Morr and mother of Shallya. She is very much a goddess of the educated and urban classes, popular in the major cities but outside them she is quite obscure except for her relationship with her husband and daughter.
Mannan the god of the sea and patron of mariniers, is known throughout the Empire but only has widespread worship along the lonely coasts of Nordland and Ostland and along the Reik as far up as Altdorf. The centre of his cult was and still is in the former Imperial province of the Wasteland and the great city of Marienburg.
Ranald is easily the most controversial of the legal deities. He is a trickster god and according to legend he was a mortal man who bamboozled his way into immortality by tricking a gullible Shallya into letting him sup from her chalice. Ranald is the god of luck, thievery and mischief beloved by all sorts of dubious characters. While his worship is not actually illegal it is frowned upon by many officials and while few of his priests end up on the stake more than one has ended his days on the hangman's rope.
Myrmidia is a foreign deity whose worship is spreading through the southern Empire. Like Sigmar and Ulric she is a martial deity, the goddess of strategy and warfare, depicted as a beautiful yet powerful warrioress. The heartland of her cult lies beyond the Empire in Tilea and Estalia where she is venerated as the most important of the gods.
There are many other gods across the Empire, some very local to a single town or village. Most humans in the Empire will probably at least know the names of the Dwarf god
Grungni or the Halfling goddess
Esmerelda even if they know nothing else about them.
There are also the illegal gods like the foul
Ruinous Powers - a subject most people don't wish to find out more about!