Rassilon Era

The Rassilon Era describes that part of the timeline during which the Time Lords ruled the planet Gallifrey and observed (but seldom interfered with) the flow of universal history. It presumably began with the ascendancy of Rassilon, founder of Time Lord society, and ended with the destruction of Gallifrey at the climax of the Last Great Time War.

The exact relation between this period and the Humanian Era, specifically whether they run in succession or overlap, is uncertain, although the TARDIS's navigational system does differentiate between the two. (DW: Doctor Who)