Attack upon the Kasterborous constellation

The attack upon the Kasterborous constellation was a battle towards the end of the Last Great Time War between the Dalek Empire and Time Lords. (PROSE: Dalek)

Prelude
The Time Lords recognised that the loss of the Cruciform to the Daleks allowed them to take the fight directly to the Time Lord homeworld, Gallifrey. (PROSE: Dalek Combat Training Manual, TV: The Sound of Drums) This incident was in fact among the unintentional side-effects of 's use of the Heavenly Paradigm, overwriting a previous timeline in which the Time Lords successfully prevented the Daleks from seizing the Cruciform and leading the Master to flee the War in fear. (AUDIO: The Heavenly Paradigm)

The battle
With the Daleks having pushed the Time Lords back to Gallifrey (PROSE: The Day of the Doctor) after an eternity of conflict, (PROSE: Engines of War) they were able to attack the Kasterborous system (PROSE: Dalek) where Gallifrey was located. (TV: Pyramids of Mars) The Dalek Emperor briefed his bronze commanders on his plans to assault Gallifrey. (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe)

Whilst a Dalek Commander involved in the engagement was killed, the attack ended as a massive Dalek victory, (PROSE: Dalek) giving the exterminators the chance to attack Gallifrey itself. (TV: The Day of the Doctor, etc.) Upon learning of the destruction of its Commander, one Dalek drone under its command came to believe the officer had died fighting bravely and that it must have died for a specific reason. With the commander dead, the drone and its squad was given a new Commander. (PROSE: Dalek)