In ancient times, the entire region was dominated by Illyrian tribes in the west, Thracians and Dacians in the east and Greek speakers in the south. The lands that later became northern Borduria were raided incessantly by the Scythians of the steppes to the north of the Black Sea and later became a client of the Greek-speaking Macedonians. Alexander the Great is rumoured to have campaigned against the local tribes before his conquest of the Achaemenid Empire.
The future Syldavia was incorporated into the Roman empire in the later Republican period and from then on looked westwards and northwards for inspiration. In the period before Diocletian ended the chaos and initiated the Dominate period of the Roman empire, a general named Gaius Fabulus Maximus was raised to the purple by his legions, but was defeated in battle by the Emperor Aurelian.
In Late Antiquity the entire region, including both Syldavia and Borduria came under assault from various barbarian groups; Goths, Avars, Slavs, Huns and Magyars all passed through the area.
Sarmatians in the 4th century and Goths in the 5th settled in northern Borduria, initially under Roman rule but later as a separate entity. However, southern Borduria remained under the rule of Constantinople until it was conquered in the 10th century by Bulgar tribes and was ruled by a series of warlords who styled themselves as Tsars. This kingdom was conquered by the Ottomans in the middle of the 14th century and remained an Ottoman possession until the end of the 17th century.
Syldavia was first mentioned as a separate and distinct location in the 11th century, when a Venetian document refers to a certain Ottonicus as Dux Syldavianum, who sent an embassy to Venice seeking trade and an alliance. Later Syldavian manuscripts in the state archives, dated to the 12th century mention a possibly legendary Budvarius, a Rex Syldavianum who had built a castle in the city of "Klovus" and founded a dynasty in the centuries after the end of Roman rule. Several Syldavian rulers are recorded in the Venetian state archives, all bearing the names of Ottonicus (Ottokar), Muscarius (Muskar) and Budvarius (Budvar). Although Syldavia spent a number of centuries as an Ottoman vassal, as well as an earlier period under direct rule from Borduria (1195-1275), it was never incorporated into the Ottoman empire and there is a text in Klow Castle, dating from the 15th century that commemorates the visit of King Matthias Corvinus to Klow during the reign of Budvar V on the occasion of his marriage to Anne de Lusignan in 1459.
There are many similarities between the two countries. Both have largely-South Slav populations with communities of other ethnicities and both speak dialects of the same Southern Slav language.
The region has long been a melting pot and this is reflected in the populations of both countries.
In Syldavia, in addition to the Slav population, there are communities of Saxons, Venetians (on the coast) and Carinthians, as well as people who trace their ancestry back to the ancient Illyrians who lived in the region before Roman times. Apart from Syldavian Slav, the other languages spoken in Syldavia are German, the Venetian dialect of Italian and an ancient Illyrian language in some of the more isolated regions in the south of the country.
Syldavia is a predominantly Roman Catholic, but with a large Orthodox population in the east of the country, some Lutherans in the north and a few communities of Muslims in the south-east of the country. These are descended from converts made during the Ottoman period.
The Syldavian aristocracy consists of three main groups. There are some families who claim Illyrian ancestry, others are descended from the Slavonic people who settled in the region in the early medieval period and a third, larger group who have southern German origins. Historically, the lingua franca of the aristocracy was German, with various languages being spoken when dealing with their subjects but in recent decades French has become more commonly-spoken by the nobility, especially at court.
The population of Borduria is broadly similar, but with notable differences. There is a quite large Turkish Muslim presence in southern Borduria, along with Greeks and some Poles, Magyars and Ruthenians in the north. There are also communities who claim descent from the ancient Dacians, Thracians and Scythians of Antiquity. There are few German communities in Borduria, except in the capital city, Szohôd, which has had a community of German merchants since the 14th century.
The Bordurian nobility is mainly descended from the Greeks of Constantinople, but there are also families of South Slav and Polish origins. Greek and German are the main languages of the aristocracy and Bordurian Slav, Ruthenian, Greek, Turkish, Magyar and an obscure Romanian dialect are spoken by the general population.
The state religion of Borduria is Orthodox Christianity, but the Roman Church and Islam are tolerated.