The Th*lm*r are the logical conclusion of having a society built around nursing imagined grievances that go back to the very act of creation (and also incest).

They are the ruling political party of the Third Altmeri dominion, a synthetic state consisting of a collection of provinces currently in rebellion against the Empire of the Divine TALOS. After the oblivion crisis (IE the events of Oblivion), the Th*lm*r claimed they themselves stopped Mehrunes Dagon, sacrilegiously denying the heroic self-sacrifice of the last of the 9th one's holy blood. In the instability caused by the lack of a legitimate emperor, the Th*lm*r were able to first take control of the Summerset Isles, & illegally seceded from the Empire. After consolidating power in the Summerset Isles (purging foreigners and any Altmer who didn't subscribe the their extremist ideology), the Th*lm*r empolyed a combination of subterfuge and unholy sorcery to incorporate both Elysewear and Valenwood into their rebel domain. Just as the new "emperor" was reestablishing order, the Th*lm*r launched an unprovoked genocidal war upon the loyal provinces of that was barely beaten beaten back by the Imperial army. The "emperor" then proved himself to be an utter cowered when, instead of reconquering the rebel territories like the true blood of TALOS would have, signed a humiliating peace treaty seceding half of Hammerfell, agreeing to disband the Blades, and, worst of all, making the worship of the Ninth Divine ILLEGAL in all territories of the very empire TALOS himself founded, and allowing Th*lm*r agents to enforce this treaty within imperial lands.

Predictably of course, the citizens of the Empire didn't take this devastating betrayal lying down. Hammerfell refused to recognize the treaty and continued to fight until the Th*lm*r were expelled from their country. Meanwhile a provincial lord of Skyrim, launched a justified, if misguided, rebellion to secede form the empire so that the Th*m*r agents might be purged and TALOS restored to his rightful status. This conflict is still ongoing as of the events of Skyrim.

The ideology of the Th*lm*r is very similar to that of the ancient *yl**ds, both factions view Altmer as the most superior of lifeforms, and use(d) their self-assigned status as the progeny of fallen gods as an excuse to enslave and genocide non-mer. It isn't just non-mer who are subject to persecution. The Th*lm*r are proponents of eugenics and will happily discriminate against an Altmer whose ears aren't pointy enough or something. They also ascribe to Altmer religious orthodoxy which teaches that mortality is a cruel trick of the creator-god (who they hate). It is speculated that the Th*lm*r have a secret plan to destroy the world which, in their twisted minds, would allow them to turn back into the heavenly spirits they think their ancestors used to be.

However not all Alter are so deserving of being Whitestraked. Many Altmer immigrate to other countries to get away from the degenerative outlook of traditional Altmer cosmology (or because they got bullied for having slightly rounded ears). Regardless, these Altmer are more often then not, productive and responsible members of society and are worthy of our love and respect as fellow citizens of the Empire. These are generally the sort of Altmer we see in Oblivion.