MMOs with existing intellectual properties, like Lord of the Rings Online or Star Wars: The Old Republic, struggle with keeping the game engaging for those who are interested in the lore and keeping it from interfering with the established timeline. LotRO interweaves the MMO plot with the classic story of Frodo and the fellowship traveling to Mordor to destroy the One Ring. SWTOR takes a similar approach to ESO by setting the MMO far in a past that contains very little established lore.
However, unlike these other MMOs, Elder Scrolls Online actually plays a significant role in the history of Tamriel. To understand this significance, we have to talk about Tiber Septim and the eight Divines.