Planetary Relocation Incident

"Ex-ter-minate! Ex-ter-minate! Ex-ter-minate! Ex-ter-minate!"

- Dalek message to Earth

The War in the Medusa Cascade was a war fought between the New Dalek Empire and other races - mostly Humans - in the Medusa Cascade. It was fought in the Medusa Cascade in an environment that held, in a pocket dimension that was one second out of sync with the rest of the Universe, in 2009.

Background
During the first year of the Last Great Time War, Davros's command ship flew into the jaws of the Nightmare Child at the Gates of Elysium. Davros, however, was rescued by Dalek Caan. Caan was the last surviving member of the Cult of Skaro, which had been destroyed by the Doctor post-Time War in 1931. After activating an emergency temporal shift for the second time, Caan entered the timelocked Time War and rescued his creator. (DW: The Stolen Earth)

Davros made Caan his prophet, and set to work reviving the Dalek Empire of before the Time War. After building the Crucible, restoring the Dalek Fleet to 200 ships, and creating thousands of Daleks with the Kaled mutants inside grown from the cells of his own body, Davros sert to work with creating a Reality Bomb. This superweapon was to destroy all of reality in every universe except for the Crucible, leaving Daleks as the only species in existence. (DW: Journey's End)

To complete this task, 26 planets and one moon were stolen from various times and places across the universe. These included Earth, which brought the problem to the Doctor's attention. The Shadow Proclamation, after the Doctor's visit to them, wanted to go to war with the unknown (to them) perpetrators of this event. However, the Doctor did not wish for a full-scale war, and left to the Medusa Cascade itself.

Invasion
Not long after the planets were brought into the Cascade, the Dalek Fleet attacked. Most of the efforts seemed to go to Earth. The Unified Intelligence Taskforce fought back, but were slaughtered. The Valiant was destroyed nearly immediately by a swarm of Daleks, and military bases across the planet were attacked and all personnel killed, except for Martha Jones, who successfully used Project Indigo to teleport away.


 * It is not clear whether any other planets were attacked by the Daleks. Other worlds out of the 27 were inhabited, and would have presumably put up a resistance.

A subwave network, made by the Mr Copper Foundation and used by Harriet Jones, former Prime Minister, was used in an attempt to help stop the Daleks. While an attack on Harriet's house followed by one on Torchwood 3 stopped the network from fully achieving this purpose, Harriet, Torchwood, Martha and Sarah Jane Smith (with the help of Mr Smith) transmitted a message to the Doctor, helping him to find the location of the stolen Earth. (DW: The Stolen Earth)

However, the Dalek assault continued. Thanks to a time lock in the Torchwood Hub, the Torchwood team survived. Sarah Jane, trying to find the Doctor, was found by Daleks but saved by dimension-hopping Mickey Smith and Jackie Tyler, who then surrendered to the Daleks to find the Doctor, whose TARDIS (with the Doctor, Donna Noble, Jack Harkness and Rose Tyler inside) had been taken to the Crucible. (DW: Journey's End)