On the last day of the Time War, the Dalek fleets surrounding Gallifrey launched what was said to be their biggest attack ever on the planet. The ten million Dalek ships subjected Gallifrey to a massive orbital bombardment and deployed numerous Daleks to invade the surface. Dalek forces captured the city of Arcadia, then laid siege to the capital itself. However, they were unable to break through the capital's sky trenches. Upon learning of Rassilon's "Ultimate Sanction", the War Doctor stole an ancient Gallifreyan weapon known as the Moment, or the Galaxy Eater, and intended to reduce Gallifrey into "rocks and dust" with the inferno wiping out the Dalek fleet. By this point, the entire period of war had become "time locked", so that no time traveller could enter or exit it.