Dalek Project
The Dalek Project was conceived by the Daleks to study human strategy and determine their weaknessess. They did this by travelling through time and analysing how humans made war throughout history. Three ships equipped with new time-drive systems were used.
However, they were caught in a Vortex storm and arrived on Earth in 1908. Survey Ship Sigma and Survey Ship Delta collided and the latter was destroyed in Siberia. The other two (Sigma and Epsilon managed to make it to Kent. They hid until 1915 when they could study the First World War. The Eleventh Doctor foiled the Daleks' plans, thus ending the Project. However Survey Ship Epsilon and it's crew were on special duties, abandoned the Dalek Project in the process.(COMIC: The Dalek Project)