Chimeran War

Origins
It is widely agreed that the Chimeran virus was carried on the meteorite that caused the Tunguska Event in 1901. The virus then began to infect local Siberians; however, only one Chimera - a local shaman - was reported at this time, transforming after months of curious symptoms (the Crawler strain would eventually evolve to get rid of the months of symptoms and produce a faster result).

Chimeran conquest of Russia
The Chimera were confined to Russia at the outbreak of the Great War in 1914, as many men (the gender that was the preferred candidate for infection at the time) were conscripted by the government to fight Germany and Austria-Hungary on the Western Border - far from the Tunguska Event region of Siberia. Therefore, they waited, all the while building up their strength from infecting the Siberians around their point of origin. Sometime after the Great War, the Crawler strain evolved, and whole settlements began to be infected. The Chimera were thorough in these small invasions, as they badly needed to build their numbers and avoid the notice of the Russian people. Eventually, they grew bolder, and soon whole cities were turned into ghost towns overnight. It was during this time that the Red Curtain was built, partly to keep Russia isolated from external affairs, but mostly to deny the Chimera a gateway to Europe. Soon most of Russia was conquered, with many of its soldiers transformed into the Cloven by Dr. Malikov in an effort to combat the virus; whilst the vaccine developed by Malikov did make the soldiers resistant to the virus, it also transformed them into entirely different creatures, who proceeded to desert the Russian army. Then the Chimera pushed towards the Red Curtain, their mysterious plan set into motion...

Seige of Genoa
The seige of genoa was a battle between italian soldiers and the chimera

During the Siege of Genoa, Italy, Italian soldiers are overwhelmed by the Chimera, whom they refer to as "the deathless plague." Many regard them as invincible, due to their extreme durability. With these facts crush the soldiers' morale. Hundreds killed themselves rather than fight, die, and possibly become the 'unholy' Chimera, contributing to the battle's loss, although it is unlikely it would have been won anyway. The end of the Siege of Genoa led the fall of Italy to the Chimera.

Chimera Invasion of Africa
the Chimera have spread across Africa at a staggering pace.The Chimera launched a series of initial attacks via airships along the northern coasts on April 6th.At the time, military analysis believed that Africa would prove too hot for the Chimera to survive beyond the coastal regions.however the Chimera have evolved newer strains of the hybrid virus along with more advanced heat radiation implants that allow their troops to withstand much higher temperatures.Once the Chimera established footholds along the coast they were able to quickly build large quantities of infrastructure, including conversion centers, and factories for producing drones, Stalkers and dropships. In the last few days the Chimera have swept across Africa with truly unimaginable speed. According to British aerial reconnaissance,chimeran forces have already begun excavation of at least twenty-three towers across the continent. Although their fuel reserves are dangerously low, the British have used naval aircraft carriers to evacuate over 170,000 African civilians from the Northern and Western coasts in the past twelve days.