1430

1430 was the year that Barbara Wright estimated that a corpse she and Susan found just outside the TARDIS had died. She did so based upon her knowledge of the Aztec Empire, which allowed her to identify the trinkets alongside the body as coming from what she called the Aztecs' "early period". Barbara quickly understood that the remains were those of Yetaxa, a figure of god-like importance to the Aztecs. (TV: The Aztecs; PROSE: The Aztecs)
According to different accounts, the First Doctor, Susan, Barbara, and Ian arrived in Tenochtitlan in 1430, (TV: The Trial of Doctor Who) 1454, (PROSE: The Left-Handed Hummingbird) or 1507. (PROSE: The Aztecs)