The 'Introduction to Elder Scrolls Online' video (embedded above) has a massive PvP siege battle which looks like hundreds or even thousands of soldiers facing off against each other. Is a battle of this magnitude actually possible in the game, made up of human players?
Every one of the figures in that video was a human player. We got all of our devs into the game for a PvP test, and then captured that sequence with them. It was all in-game. Cyrodiil (the PvP map) is open-world and supports up to 2000 players in it at the same time. ESO’s client is designed to be able to handle (on the recommended spec) 200 players on screen at the same time. That particular scene had about 115 players on each side.