Removal of the Thals

At some stage in the Daleks' timeline, the Daleks oversaw the removal of the Thals from their respective home planet of Skaro.

Background


In the centuries following the failure of Project Degravitate during the 2150s Dalek invasion of Earth, the Daleks had spread to Skaro's neighboring star systems, mining the planets for materials. In doing so, they committed a grave tactical error by neglecting defense of Skaro, having underestimated the Thals; since their homeworld was worn down and they had no particular attachment to it, they assumed this would be true of others. The Thals, however, were grimly determined to regain their homeworld, and they managed to launch an assault from their colony planets back at Skaro. As a result of Dalek laxity, the Thals managed to seize their planet back again, destroying all Daleks based there at the time. This assault severely crippled the Thal war efforts, for they were still a peaceful people. The Thals, however, understood that they would never know peace until the Daleks were destroyed and felt a deep guilt that part of the blame for the creation of the Daleks rested upon them, vowing to sweep the galaxy free of their enemies. Accordingly, they began to develop deep-spaceships of their own, ready to strike and cripple the Dalek forces whenever they could. In the captured computer files, they discovered details of the Dalek communications system, which they modified so they could monitor their foes. It was from this that they learnt the Daleks were maintaining secret base on the planet Spiridon. (PROSE: The History of the Daleks)

The Removal
Whilst considering the development of time technology, the Daleks' immediate concern was the removal of the Thals from Skaro. Whether the Daleks truly had no sentimental attachment to their home planet (PROSE: The History of the Daleks) or if Davros was right, as the scientist would later claim the Daleks would always work to restore their homeworld, (TV: The Witch's Familiar) the Daleks were unwilling to allow the Thals to remain established there, knowing that they would form a second front to attack them. The Dalek Prime deemed that the simplest solution was the mass bombing of the planet, rendering it lethal. As before, the Thals learned of this plan by monitoring Dalek communications. Knowing they had no chance at all of stopping the Dalek attack, the Thals resolved to abandon Skaro again.

To prevent the Daleks from realising that they had escaped, a small number of Thal troops remained behind to stage a fairly convincing defense of Skaro in what was effectively a suicide mission, buying time for their people to retreat and consolidate before fighting the Daleks another day. The small band of volunteers fought long and hard, but ultimately fell to the massed Dalek firepower. The Daleks dropped several neutron bombs on the Thal settlements, not realising they were already abandoned. (PROSE: The History of the Daleks) Indeed, the Time Lords understood that Thals were eventually forced off Skaro by the Daleks, theorising that they had sought refuge in a series of off-world colonies. (PROSE: Dalek Combat Training Manual)

In the aftermath, the Daleks completed their first time machine which they used to pursue the First Doctor through time, only to become embroiled in the Mechon Wars. (PROSE: The History of the Daleks)

Aftermath
The Thals eventually relocated to another homeworld New Davius, (AUDIO: Brotherhood of the Daleks) some time before the Imperial-Renegade Dalek Civil War, (COMIC: Emperor of the Daleks!) although they occasionally returned to Skaro for brief visits. (AUDIO: Scorched Earth)

In their absence, Skaro was believed to have been destroyed, (TV: Remembrance of the Daleks) though according to the account of the Dalek Prime in actuality a decoy world named Antalin had actually been destroyed. The Thals survived past Antalin's destruction and fought the Daleks on Terakis and wiped out half of the Dalek Eighth Fleet. (PROSE: War of the Daleks)

Whilst still residing on New Davius, the Thals allied with the Time Lords to fight against the Daleks in the Last Great Time War. (AUDIO: Temmosus)

Thals lived on the rebuilt Skaro in the post-Time War universe. After escaping the Dalek City during the Hybrid Incident, allowed her pet Slyther, who she named Doctor, to eat the Thals they came across. (PROSE: Postcards from the Universe)

Behind the scenes

 * The Terrestrial Index stated that the Thals were "exiled" from Skaro before eventually "reconquer[ing]" the planet during the Second Dalek War in the 25th century, forcing the Daleks to adopt a replacement homeworld. Ultimately, following the Third Dalek War, the Daleks launched a new attack on Skaro, before the end of the 26th century, in which they exterminated most of the Thals, leaving the planet a bombed-out ruin which would be not be of use to the Daleks until the Movellan Incident.