Old Time

The Old Time refers to the time on Gallifrey before Rassilon had created the Time Lord civilisation. In this time, Rassilon fought the vampires throughout the Universe (DW: State of Decay) and with Omega created the Eye of Harmony (DW: The Three Doctors), validium (DW: Silver Nemesis), and the Hand of Omega. (DW: Remembrance of the Daleks)

Gallifreyans had the ability to reproduce during the Old Time. When the Pythia cursed them with infertillity, they created Looms. (NA: Lungbarrow)

Lady Peinforte threatened to reveal the Doctor's secret "from the Old Time". (DW: Silver Nemesis)

There is speculation about if this secret may be the nature of the Doctor's birth, as revealed in DW: Doctor Who by the Doctor. Russell T Davies, in an earlier script for DW: The End of Time, would have discounted this idea by having the Doctor say it was a "48-hour bug." (Doctor Who Confidential)