Timeline

2240: Curling first discovers the Aethralons. He also improves cryonics for personal use and invents a stable strain of FEV that improves combat efficiency but still at the cost of mental deterioration.

2241: The Oil Rig is destroyed. Curling murders President Richardson and escapes to Navarro.

2247: Damien's father underwent experimentation and as a result became immortal.

2254: Damien meets Ophelia. Anthony was exiled from the Enclave and Damien was promoted around this time.

2256: Beatrice is born, causing a commotion within the Enclave. Damien is promoted again from general to branch general and is elected as the momentary leader of the Enclave. Ophelia is granted protection by High Command despite being a Khan. The Chernov family gains a superior ranking within the Enclave for the first time in a century. Chernov Senior is awarded the medal of honor and a purple heart for his service in the 'New Cali Purge'.

2281: The 2nd battle of Hoover Dam was fought, with the NCR and Legion being pushed out of the Mojave. The Courier made and ruled an independent New Vegas.

2282: The Courier and Ulysses launched the Divide nukes, turning the land from Nevada to the far coast of California into scorched earth and ash. Elijah invaded the Mojave with the Cloud and the inhabitants of the Sierra Madre. An unknown mutated variant of FEV and other diseases began to plague the Mojave, victims were called "Infected". The basic diseases consisted of rad poisoning and Cloud sickness, radiation was curable depending on the level but Cloud sickness was not. Victims were terminated without question and their bodies would either be incinerated or dumped somewhere far away from populated areas. FEV infectees were a much more complicated threat, as it seemed to cause a zombie-like effect in its hosts and was unexplainably much more lethal to females.

2283: The Ghost-Raider war began, resulting in eradication of all remaining raiders and tribals.

2284: Mr. House is active again and strikes a deal with the arriving Enclave forces. House was also elected president of the U.S and the Enclave by the end of this year. Eden appeared sometime halfway through this year and became a High Command member. The Courier retained his role as House's assistant and personal courier. Brandon arrives and is the highest ranking field officer at the time, making him the standing commander of Enclave forces until someone else comes along. Damien, Nikolai and Vincent arrive as members of High Command after Nova murdered the previous group. Monochrome attacked the Strip and was destroyed a week after.

2285: The Ghost-Marked war began, resulting in heavy casualties on both sides. The New order had progressed significantly as a government and military power. The Reaper project began sometime this year. The New Order developed multiple new armors and weapons, but most of them never left the prototype stage. Regardless, all the prototypes work as intended, but aren't quite finished yet.

2286: Hidden Valley, Camp McCarran and an unmarked NCR bunker were attacked and destroyed by the Enclave. BoS Elder McNamara and NCR President Aaron Kimball were killed by Brandon, finally getting revenge for his family who were killed by those two leaders.

2287: Samael, Michael, and presumably Ashley and Beatrice escaped an Enclave lab. Its unknown why Beatrice was there or what she was there for.

2288: The New Order fell at some point during this year. Eden was shut down, and all New Order projects were stopped. At this point, most Reapers were neutralized and were an ally of the Enclave, but some still remained murderous and destructive.