70

According to the Sixth Doctor, 70 A.D. was the year the Romans began construction of the Colosseum. (PROSE: State of Change)

In the early 21st century, archaeologists found a Roman mosaic that they dated to this year. On the mosaic were scenes, grapes and a Dalek. This suggests that there were Daleks on Earth in the 1st century AD. (PROSE: I Am a Dalek)