Timeline

Timeline - The history of Oceania is veiled in obscurity, due to the diligent history-forging of Minitrue. This much is known, though:

1950s: Great purges in which evidently several thousand Britons perished. (Winston's vague childhood memories; he remember that his parents disappeared in these purges.)

Early 1950s (at the earliest 1950, at the latest 1955 or 1957): The time of the Atomic Wars. Several cities in North America, Europe and Russia were attacked with nuclear weapons. Colchester in Great Britain, not yet Airstrip One, was bombed in a suprise attack. (Since the novel was published in 1949 and wasn't intended as a uchronia, the wars may not have come earlier. Winston is 39 years old, and thus born 1945; his vague memories suggest that Colchester was bombed when he was 10-12 years old or possibly younger, which would mean that the war would have taken place 1955-1957 at the very latest.)

Mid-50s (approximately 1954-1957): Evidently a time of civil war in Airstrip One, then Great Britain; shortage of food, air raids, street battles, authoritarian movements fighting for power. The first labour camps appeared at this time, possibly earlier. (Winston's vague childhood memories.)

1957: This can possibly be the year Ingsoc seized power in Airstrip One. If this also meant the formation of Oceania remains unclear. (The novel mentions the "overfulfillment of the Ninth Three-Year Plan".)

Around 1960: The name Ingsoc appeared for the first time, but the name "English Socialism" may have been used before this year. Whether this means that Ingsoc seized power around this year or simply changed its name is uncertain. (Winston's vague recollection.)

1963: This year, Oceania was probably at war with Eurasia. (In the false charges against Aaronson, Rutherford and Jones, it's claimed that they met Eurasian generals this year. This is Winston's own and clear recollection, and thus fairly plausible information.)

Mid-1960s: Great purges in which the old Ingsoc leaders were wiped out. By the year 1970, not a single one remained, possibly with the exception of Big Brother - if he exists. (This is Winston's own and clear recollection, and thus fairly plausible information.)

1965: This year, Oceania was at war with Eurasia. (The false charges against Aaronson, Rutherford and Jones involved espionage for Eurasia. This is Winston's own and clear recollection, and thus fairly plausible information.)

Before 1980: Oceania was at war with Eastasia and in alliance with Eurasia. (Winston's own and clear recollection, and thus fairly plausible information.)

1984: After being at war with Eurasia and in alliance with Eastasia for about four years, Oceania enters an alliance with Eurasia and declares war on Eastasia. (See the scene in Victory Square.)