The overall reason is the see which side will outnumber the other that is what the conflict during the period that ESO is taking place.. Its a race to recruit the dominion, we are the community and even the forums are Tamreil itself before the war starts over the Ivory Tower.. no matter what it looks like its The Elder Scrolls. The lore included not much was really said about this time. We are writing the lore as we play and discuss we are making the game by deciding sides. When you complete one faction you can go to another after battles fighting with other members for of a previous faction as a recruitment into a opposing side.. Its Brilliant.. What do you think Community of Tamriel?