4500

4500 (PROSE: Resurrection of the Daleks) was the year the Daleks returned to Skaro to revive Davros in an attempt to win the Dalek-Movellan War. It was also the start of Davros's imprisonment in suspended animation for 90 years. (TV: Destiny of the Daleks)

Behind the scenes
The Dalek Handbook had dated the Movellan Incident and the Duplicate Incident to 4500 and 4590 respectively.