When the Mongol horde tore through Eurasia, they brought with them a strange and horrifying disease. This disease attacked the nervous system of the victim, driving them mad and turning them into cannibals. Bites spread the disease further, making each victim of an attack a potential threat later on. While infectees were most certainly alive, and later studies showed perfectly cognizant of their actions, the people who suffered from the plague's effects believed that the dead were rising. And so, the plague was called the Black Undeath.
The Mongols saw potential in this disease and hurled the infected into fortified cities. Those cities that did not surrender were quickly overrun with infected. Eastern Asia and the Middle East were utterly devastated, but Europe was fortunate enough to stay in the Mongols' good graces by organizing strategic alliances with them against the Muslims. The Mongols became masters of Asia, and Europe took advantage of the Islamic world's weakness by launching a series of successful crusades.
The Roman Empire, based in Constantinople, came close to reunifying the empire in the 1400s before an outbreak of plague demolished it, but the Romans still held firm control over most of the Middle East until the Jerusalem Revolt of 1745. The English won the war of the thrones with France, taking control of much of France proper while taking over the British Isles. France never recovered. The Spanish and the Andalusians formed colonies in the New World, called Vesperia and Avalon, and kept control of most of Vesperia until the Iberian Unification of the 1800s. The Italian states of Genoa, Venice, and the Kingdom of Two Sicilies would attain colonies and establish trade routes throughout the New and Old Worlds, competing with the Dutch.
By 1913, technology such as tanks and aircraft were commonplace. The world was divided roughly between the republican and monarchist blocs, although this broad ideological rivalry was not as strong as comparable “cold wars” in other worlds. The Avalonian Federation, descended from English colonies in Avalon, dominates the Western Hemisphere. A large, federated democracy, Avalon sees itself as the protector of Avalon and Vesperia, but does not find much of a role outside of the New World. The republics of Iberia and Venice are close allies and two of the richest countries in the world. Both are fairly free, but are dominated by old families and corporate interests in officially oligarchal governments. Where both lack in population and military strength, both make up for with riches and a large network of allies. Rivaling the republican bloc in Western Europe are the English and the Dutch, a set of monarchies who nonetheless dislike Constantinople. Slightly weaker than the Lisboa Pact, the English and Dutch nonetheless pose a threat in Western Europe.
Central Europe is dominated by Germany, which unified in the 1700s. While it does not always see eye to eye with the Lisboa Pact, it does have a stronger rivalry with the autocratic Romans and Muscovians. The Divine Agreement is a loose association of the Constantinople’s and its closest allies: Rome, Persia and Aragon-Sicily. The Divine Agreement sees republicanism as a cancer upon the world, although their actions do not reflect this ideology. Affiliated with the Divine Agreement is the autocratic Muscovy, the largest country in the world. The largely independent Kingdom of Jerusalem, a Catholic descendant of the old Crusader states, has reconciled with Constantinople but is still a bit paranoid about Rome’s ambitions.