The rift going from thanes to a jarl.

Khold90 · July 28

So, the dawnguard were formed in the late 2nd era after the jarl of the rift had his son go down into the vampire pit currently in the ratway, become infected and then become jailed.

As much as there is still 300 ish years left of the 2nd era it would be cool to see the very beginnings of the faction, as well as potentially early prototypes of crossbows that aren't a single ability.

Tyrvarion · September 21

I think ESO already implies that those events happened before it (after all we are in nearly 600th year of era that lasted 800ish). One of FG weapon abilities speak of Dawnguard as if they are already formed. So I am positive dawnguard are already an operational faction.

KingArthasMenethil · November 24

We don't really know. Base game ESO kinda forgot about the Riften Jarl. Western Skyrims prologue mentions a Jarl during the Ratway section but we never see one. In theory the events could be ongoing but we simply have zero in universe explanation. The Fighters Guild has a skill called Dawnguard crossbow but I don't base skills off much since they could be doing whatever they wanted.

Ideally the Dawnguard would really be a dungeon dlc since you'd probably be attacking the place to deal with the Vampire son.