Board Thread:Online Discussion/@comment-5031926-20130603014837/@comment-7153552-20130603211409

Something else to remember is that this site isn't official, nor is it governed by Bethesda, Zenimax Online, Zenimax Studios, etc. People can put things that are half-true based on their limited understanding of lore and cannon. However, I have, for your lore and reading pleasure, the direct quote from the source noted on the wiki page for the Forsworn (Online):

"The Forsworn are a faction of the Reachmen that exist in the Fourth Era during the time of Skyrim. While the Reachmen are mainly of Breton stock, they have their own culture and society and don’t consider themselves Bretons – and the Bretons agree. The Reachmen definitely appear in ESO, as they’ve allied themselves with dark Daedric forces that have sacked the Imperial City. Reachmen clans have been giving trouble both to the Bretons of the Daggerfall Covenant and the Nords of the Ebonheart Pact."

The whole Q&A can be found here.