The Rani

Ushas, later known as the Rani, was a renegade Time Lady. Knowing both of them in youth, she grew into a rival to the Master and opponent to the Doctor.

Youth and Exile
The Rani was the same age as the Doctor. (DW: Time and the Rani) On the planet Gallifrey, at the Academy, she belonged to a clique of six young people who called themselves the Deca. Apart from the Doctor, her other future enemy Koschei (later the Master) belonged to this group. (PDA: Divided Loyalties)


 * A past relationship between the Rani and the Doctor was hinted at, but never elaborated upon.

Unlike the other members of the Deca, she did not chose to leave Gallifrey but was exiled from the planet after some of her lab mice, as a result of an experiment, grew to enormous size and ate the President's pet cat. (DW: The Mark of the Rani)

Presence in Earth history
While the Rani certainly did not share the Doctor's fondness for Earth (she referred to it as a "miserable planet") it has been the focus of several of her research projects.

When the test subjects on Miasimia Goria, a planet she had enslaved, became violently restless and uncontrollable as a side affect of her experiments on them, the Rani visited Earth at various points in its history to extract chemicals from the brains of select Human specimens. Because the chemicals in question enabled the human brain to sleep, and because the absence of these chemicals made her victims as violent and uncontrollable as those from her previous experiments, the Rani deliberately chose periods of social unrest to visit, using the violence to conceal her presence and its consequences. She visited the siege of Troy, the Dark Ages, the American War for Independence, and finally the Luddite riots in the village of Killingworth during the early 19th century.

Prior to this arrival she had visited Earth in the late Cretaceous and acquired several Tyrannosaur embryos. (DW: Mark of the Rani)


 * The Rani's comments concerning the unrealised full potential of the dinosaurs are curious given the existence of the Silurian civilisation on the planet at around the same time. She may have been obliquely alluding to averting the fall of the Silurians. Then again, as a biochemist she may simply not have been that familiar with social sciences such as history and just wasn't aware of the Silurians' existence. This seems unlikely, however, given her apparent visits to the Cretaceous to gather specimens.

The Master and, shortly after, the Doctor interrupted her work. The Doctor sabotaged the navigational system of the Rani's TARDIS, trapping the Master and the Rani inside as time spillage caused the Tyrannosaur embryos to grow at a dangerous rate. (DW: The Mark of the Rani).

On Terra Nova
Shortly afterwards, from the Doctor's subjective point of view, the Rani was also trapped along with the Doctor on the alternate Earth of Terra Nova which the entity known as Iam had created. She had in the meantime tried and failed to manipulate the political situation existing between the three children of that reality's version of Cleopatra ("State of Change")

On Tetrapyriarbus and Lakertya
On the planet Tetrapyriarbus, made the acquaintance of, and decided to employ the Tetraps, led by Urak. With them, she invaded the peaceful planet Lakertya and put into motion a complex plan. The Rani abducted eleven scientific geniuses from across time and space, including Albert Einstein of Earth. Finally, she decided to "collect" the Doctor and attacked his TARDIS, causing the ship to go through turbulence and hit his head, triggering a regeneration into his seventh incarnation. (DW: Time and the Rani)


 * ''Conflicting account suggest the Doctor did not actually regenerate strictly because of the Rani's attack on the Doctor's TARDIS.

The Rani channeled the intellects of the geniuses a giant artifical brain which she believed could find the secret to manipulating strange matter in order to make the planet of Lakertya Time Manipulator in order to correct what she considered to be errors in the universal timeline. Her first target was to be Earth, where she would prevent the extinction of the dinosaurs, creatures whose full potential she felt had never been truly realised. She considered the death of the native Lakertyans a small price to pay. The Doctor, though, defeated her and the Tetraps turned against her and imprisoned her on their home planet. (DW: Time and the Rani). The Rani did manage with the help of the very persons upon whom the Tetraps instructed her to experiment (BBV: The Rani Reaps the Whirlwind)


 * We do not know the Rani's ultimate fate. However, with all Time Lords save for the Doctor killed in the Last Great Time we can conjecture that the Rani also died. Some have conjectured that she survived and took the Master's ring from him following his cremation.

Possibly apocryphal adventure
One account claims that, with her assistant Cyrian, the Rani later captured the Doctor's first and second incarnations. Despite his fourth incarnation attempting to warn them of danger, the Rani managed to lure the Doctor's other selves (as well as his companions) into a temporal trap in order to include them in her menagerie of creatures. She hoped to shortly complete her collection of genetic samples and brain prints of every creature in the uinverse With the help of the Doctor's time brain, she hoped to gain access to and control of every individual mind in the cosmos. (DW: Dimensions in Time)

Personality
An evil scientific genius whose villainy comes not from the usual variety of lust for power and suchlike, but from a mindset that treats everything (including morality) as secondary to her research; she has been known to enslave entire planets in order to have a ready supply of experimental subjects and a place to carry out her experiments uninterrupted. Her major interest is in tinkering with the biochemistry of other species.