The Humanian Era describes that part of the timeline during which humans played a significant role in the history of Mutter's Spiral and eventually the Universe. Assignments of its beginning date vary, though many place it circa 200,000 BCE, when modern Homo sapiens first appeared on Earth although it is possible that the humanian era began when mankind started to develop space travel, according to the War Lords("The War Games"). The Humanian Era ended around 10 billion AD, when Earth had long since been destroyed by its expanding sun ("The Ark," "The End of the World"), and other races, such as the Chelonians, had begun competing for dominance with the human race, which had by then spread out rather thinly across the Universe.
Study of the latter years of this era was forbidden by the Time Lords, as it lay outside their sphere of influence ("The Well-Mannered War"). The exact relation between this period and the Rassilon Era, specifically whether they run in succession or overlap, is uncertain, although the TARDIS's navigational systems does differentiate between the two ("Doctor Who: The TV Movie").