Giving someone the finger is a gesture that was already used in 423 BC

Giving someone ‘the finger’ was used by the ancient Greeks in their comedy plays to insult another person. This gesture is recorded in Roman writings as the digitus impudicus, the impudent finger. Literature most often points to the comedy ‘The Clouds’, written by Aristophanes in 423 BC as the first appearance of this gesture.
It was defined there as a gesture intended to insult another person.
The widespread usage of the finger in many cultures is likely due to the geographical influence of the Roman Empire and Greco-Roman civilization. Another possible origin of this gesture can be found in the first-century Mediterranean world, where extending the digitus impudicus was one of many methods used to divert the ever present threat of the evil eye.

Source: Wikipedia