Thal-Dalek War

The Thal-Dalek war was a conflict between the Thals and the Dalekss which lasted over a long period of time, however very few events are known to have happened in the duration of the war.

Duration
Some time after the Thousand Year War, the planet Skaro had been changed into a nuclear wasteland with the principal features being the Petrified Forest of Skaro, where the Thals lived, and the Dalek City. The Doctor and his companions, Ian Chesterton, Barbara Wright and Susan Foreman, visited Skaro at this time and led some of the Thals to attack the Daleks in their city, disabling the power generator and depriving the Daleks of the static electricity they needed to move about the city. (DW: The Daleks)

However, the Daleks somehow survived and, probably circa 2540, the Daleks built a base on the planet Spiridon, and planned to launch an army of ten thousand Daleks, made invisible by Spiridon technology, across the galaxy. Again, the Doctor led the Thals to defeat the Daleks, this time using the ice core of the planet to freeze the Daleks. (DW: Planet of the Daleks)