April 26, 1986: At around 1:23 in the morning, reactor number four of the Chernobyl Nuclear Power Plant explodes, releasing dangerous radioactive materials over a widespread area, and forcing the evacuation of the nearby city of Pripyat and other settlements. This event is known as Chernobyl disaster.

After the accident, groups of workers called 'Liquidators' are hired by the Soviet Union to build a containment building around the remnants of the Reactor 4. It was later nicknamed the Sarcophagus.
As a safety precaution, the Soviet Union establishes a 30km "exclusion zone" around the CNPP disaster site. The zone extends into both Belarus and Ukraine.

December 26, 1991: The collapse of the Soviet Union. Several republics break away from the USSR, declaring independence, many projects are discontinued, in particular funding for Soviet military labs in the Zone.

~2005: Unnatural weather patterns reported at and around the Exclusion Zone, including hurricane-force winds and tremors.

March 4, 2006: Blinding light illuminates the sky high above the Chernobyl Nuclear Power Plant. The incident lasted two full hours before subsiding, with witnesses reporting it disappeared as if power suddenly failed.
//Video Evidence #1
//Video Evidence #2
//Video Evidence #3

April 12, 2006 14:33 +2 GMT: Just over a month later, the skies are once again lit by intolerably bright light. The clouds evaporated from the sky, followed by a tremendous thunder crash, lasting far longer than normal. After the thunder faded away, there was an ominous silence, followed by a 6.9 Richter earthquake. The glow in the sky continued, spreading over the entire region, while deadly energy disturbances raged through the Zone, making any rescue effort impossible. Subsequent investigation turned up the fact, that the center of the explosion was a kilometer away from the nuclear plant itself, evidently the nuclear fuel dump going up.

~2007: Reports rise of kidnappings inside both Belarus and Ukraine, with seemingly no connection. A total of 75 individuals are reported missing in a two-month period. Investigations are still on-going.

~2011: With news of the possibility to survive in the Zone leaked, amateur researchers, marauders and poachers begin to make their way into the zone, soon becoming known as stalkers, seeking artifacts in the dangerous environments. At first ignoring them, the government is soon forced to re-evaluate their policies, as artifacts make their way into private hands.

February 4: The government retaliates against illegal stalkers, during this campaign over 70 are arrested and ten trading posts closed down.

October 25: Inevitably, a skirmish takes place between a military patrol and a stalker group. Both sides suffer serious casualties, the army is authorized to shoot stalkers on sight.

July 13th, 2012: Operation Fairway is conducted by Ukrainian Armed Forces into the exclusion zone, resulting in a total failure.

March 4th, 2014: The Russian Federation annexes the Crimean Peninsula from Ukraine. Sightings of Russian Spetznas are reported inside the Zone.

~2015: A global recession originating in the United States begins, heavily affecting Eastern Europe.

~2017: Local sightings of 'humanoid monsters' inside and around the exclusion Zone are reported. Russian troops stationed inside the Crimea, as well as unofficial reports from stalkers match descriptions of Ukrainian locals.
The Ukrainian government is alleged to be conducting genetic modification projects inside the safety of the zone. The government denies such projects. A United Nations inquiry concluded no such projects were conducted.