Fall of Arcadia

The Fall of Arcadia was a battle fought on the last day of the Last Great Time War. Part of the Daleks' final attack on Gallifrey, the Dalek victory in Arcadia marked a major advancement in their effort to defeat the Time Lords and win the Time War.

History
The city of Arcadia was thought to be "the safest place on Gallifrey", because it was protected by 400 sky trenches. (TV: The Last Day)

Eventually, a massive Dalek force of Dalek drones, Dalek Attack Ships, and Dalek flying saucers managed to effortlessly penetrate the trenches, destroying the once-proud city, whilst the Time Lord soldiers fought back in desperation. (TV: The Last Day, The Day of the Doctor) The battle was horrific. (TV: Doomsday) Crushed by rubble, ripped apart by enemy fire, or simply left broken in the dirt, the corpses of Time Lords and the remains of Dalek casings alike came to litter the city. Dead Dalek mutants could even be seen through the battered casings. (PROSE: Dalek)

Bowships were used at Arcadia, but failed to prevent its fall. (PROSE: A Prologue)

The War Doctor was at Arcadia, fighting on the front lines. He was glimpsed by a Dalek drone which was so overcome by fear it had began firing aimlessly, missing him entirely. (PROSE: Dalek) Witnessing the devastation, the Doctor blasted the words "NO MORE" into a wall as a message to both the Daleks and the Time Lords, and departed to steal the Moment with the intention of ending the war once and for all. As he departed, he used his TARDIS to ram down a group of Daleks, saving the lives of a group of people they had cornered. (TV: The Day of the Doctor) The invasion all but destroyed Arcadia. (PROSE: The Whoniverse)

It was also during the Fall of Arcadia that the Eye of Time, the singularity at the heart of the Time Lords' power, was "lost". (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe) The Eleventh Doctor was aware of the loss of the Eye, and told Amy about it after the New Dalek Paradigm recovered the Eye long after the Time War's end, although he did not mention Arcadia by name. (GAME: City of the Daleks)

Legacy
When he mentioned being present at the battle to the Cult of Skaro in his tenth incarnation, the Doctor claimed he still hadn't mentally recovered. (TV: Doomsday)

The Fall of Arcadia was remembered to have occurred in the final moments of the Time War (PROSE: The Secret Lives of Monsters) and was depicted in the Time Lord painting Gallifrey Falls No More. (TV: The Day of the Doctor)

Behind the scenes
Prior to The Day of the Doctor, Arcadia was presumed to be a planet that was devastated by the Time War. Specifically, Doctor Who: The Encyclopedia stated that the Doctor watched as the Daleks fled from the planet.

Chute d'Arcadia