Overall, geography and ethnicities are not so much different than those in our world. Suntolia is a mix of Simeon the Great and Asen dynasty Bulgaria, Karet is based on Kievan Rus, while Volniya - Great Moravia and the Polish - Lithuanian commonwealth. Thus the main cast is white Eastern Europeans.
Suntolia is located in the South, in the Suntolian peninsula, even though, it is not the only nation on it. With a sea on the east and south, Karet on the Northern border and smaller nations. Suntolia is divided into 13 regions - one is the capital, while the other 12 are ruled by the 12 great knyaze. Kostica, ruled by the Petrosinovi is located in the north-central, just below the capital region, serving as a last stand if the capital gets taken over. Zhegavica, where Delyana lives is located above the southern sea. The population is mostly suntolian, with villages near borders having a population from the neighbouring nations as well. Merchants from other nationalities live in the capital, as well as bigger cities serving as trading centres. When it comes to looks, you can say are rather "diverse" in their looks. By that, I mean different hair and eye colour combinations, though dark hair and eyes is the most popular one. The skin colour is white and even when one is referred to as tan or olive-skinned he would still be still white to people of colour. The Petrosinovi's turquoise eyes and silverish brown hair is not reserved features for them only, but can be found in some people in Kostica as well. It is just that these features are seen in almost every member of the family.
The religion is similar to Orthodox Christianity and Slavic paganism, just like that of Karet. The navy is not developed as the infantry, as Suntolians don't show much interest in it or navy trade much. They trade with closer eastern countries (based on Islamic golden age middle east), as well as Volniya, their smaller neighbouring nations, but for the most part, rely on whatever they make themselves. In the first chapter Kalina and Beloslava peel peppers and Delyana eats a tomato - though not native on the Balkan peninsula, they have become an important part of our diet. In this world, when western travellers started exploring what lies west of the sea they were a bit smarter and started trading fairly with the native people, sharing knowledge with each other, thus importing some new types of crops and spreading them over the continent.
Karet is located in the East, spreading from North to South. It has had a long hostile relationship with Suntolia, but for the past few decades, the two are in a fragile peaceful relationship. Their looks are mostly pale-skinned, blondes, but dark-haired people are not uncommon. Their trade is mostly with the East as well. Their northern navy is developed better than the southern one, while their infantry is praised even by Suntolians. Ruled by a tzar, his power is not as centralised as that in Suntolia, even though he still has a big control over the nobility.
Volniya is located in the west, sharing a border with Karet's North, but their relationship is rather hostile, thus creating a peace treaty with Suntolia by offering the hand of Bozhana to their king. Their looks are similar to those of Karetians. Their trading is mostly with their western and northern neighbours.