Dalek Wars

The "Dalek Wars" were the series of conflicts that involved forces of the universe, primarily humans, battling the Daleks. These included the invasion of Earth in the 22nd century, also known as the First Dalek War, (PROSE: Prelude Deceit) the Human-Draconian War in 2520, the Second Dalek War, (TV: Frontier in Space, Planet of the Daleks) and the Third Dalek War which took place prior to Steven Taylor's time, centuries prior to 4000. (PROSE: Mission to the Unknown) These conflicts put a stop to Earth's expansionist era. (PROSE: The Chase)

The Third Doctor recalled meeting the Thals on Skaro during "the Dalek war", which Vaber recalled took place generations prior to 2540. (TV: Planet of the Daleks)

Peter Hamilton's father was killed in a Dalek war. (TV: Death to the Daleks)

A war was fought between the Daleks and humanity, leading the Combined Galactic Resistance. (TV: Into the Dalek)

A war between humans, defended by the Space Security Service, and the Daleks had raged for a hundred years into the 41st century. (COMIC: The Only Good Dalek) Daleks which were engaged in a conflict which humanity traveled back through Earth's history where they conducted the Dalek Project to understand how humans fought. (COMIC: The Dalek Project)

A Velyshaan museum contained an exhibit on the wars after the Second Great Dalek Occupation. (PROSE: Museum Peace)

From the perspective of humanity, the Daleks suddenly disappeared "thousands of years" prior to the Battle of the Game Station in 200,100. As recalled by Jack Harkness, a former Time Agent from the 51st century, the Daleks vanished from time and space at a point when they were the "greatest threat in the universe." As the Ninth Doctor recalled, they had left to fight the Last Great Time War against the Time Lords. (TV: The Parting of the Ways)

By the far future, circa 10,000,000, the Daleks were considered a part of the First Segment of Time. (TV: The Ark)

According to the Daleks themselves, the "creatures" of 500,000,000 knew nothing of them. (PROSE: I Am a Dalek)

Behind the scenes

 * According to Lance Parkin's Whoniverse: An Unofficial Planet-By-Planet Guide to the Universe of the Doctor, from Gallifrey to Skaro, the script for Into the Dalek specifies that the story takes place in the 31st century.