What is the origin of the middle finger gesture, in the context of being construed as an insult?

by ZoggerXIII

a co-worker and I are debating the origin of the middle finger, he claims that it originated with medieval trench archers ofdering their draw fingers as a sign of defiance. Can AskHistorians offer any insight?

Searocksandtrees

Hi, you may be interested in this earlier reply by /u/ragleur