What religion has the longest (or greatest) history of violence? SEE DETAILS BEFORE ANSWERING, please?

The first is violence and the second is the longest. Both are subjective. In the first place violence and be interpreted in many different ways and perhaps not in the way you probably intended.

But if you mean military violence I might say the Catholic church is the oldest and most violent, it launched military crusades to conquer the Holy Land for religious and political reasons. , and it constantly used military and coercive force to put down heresies and to bring the word to heathan nations. The Catholic Church is @ 17 centuries old since the time of Constantine who, by the way wore the Cross on his Armor along with his men, at the Battle of Malverne Hill.

Islam, on the other hand, is younger, only 13 centuries old ( most people will probably cite this religion as being the most militarily violent). But there is an even older religion that used military violence to establish itself and and achieve dominance among its neighbors, Judaism. Assuming the history presented in scriptures are true, the violent conquests, including putting the enemy to the sword, men women and children, was initiated with Joshua and the conquest of the Cananites by the 12 tribes of Israel after the Exodus.

This military violence then continued against the Philistines, Syrians, Assyrians, Egyptians, Babylonians, Syrian Greeks, Romans, Christian Crusaders and Arabs. Judaism is @ 33 centuries old counting from the time attributed to the Exodus by most scholars or 26 centuries old from the time of the historically chronicled Judean state where the worship of Yahwey becoame the state religion in the reign of King Josiah. But what of other forms of violence.

As history is subjective, interpretations often vary greatly. Killing animals is violent. Ripping the hearts out of prisoners of war to appease the Sun God is violent.