Exactly how powerful was Dagon's army during the Oblivion Crisis? I know they were powerful enough that the Empire withdrew from Morrowind to fight the Daerda, but in the games you never get a good scope for the size of their forces. (I really doubt his army consisted of a Scamp and a Daedroth in a Colovian field, after all...)

And what was the Empire's forces like then? Again, in the games I see no real presence of an army, rather just the Imperial Legion.

Dagon's forces were strong enough to flatten Tamriel, but not strong enough to take Argonia.

And Argonia is...? Capital of Black Marsh? (Random guess)

Summurset Islands were being defeated by them. They had impressive siege machines (just look at Kvatch to see their effects), and hordes of powerful Daedra, mainly Scamps and Dremora. Also, he had Mythic Dawn agents messing things up, serving as sleeping agents, demolishing the barriers between Mundus and Oblivion by killing Uriel... Their numbers were almost infinite, I think

Argonia is an alternate name for Black Marsh. The Hist hulked up the Argonians when the Daedra invaded and they swarmed into the Oblivion gates in such numbers that the Daedra ended up closing them from within just to get rid of them.

Otherwise, the Daedra were able to destroy Ald'Ruhn, the council seat of the greatest military on Vvardenfell (and given that Kvatch was supposedly the opening shot of the invasion, they probably had some warning as well). So the Daedric forces were evidently quite formidable.

It′s another name for Black Marsh, the meric one.

On topic: Their strength was not their numbers, but that they were without fear (atleast the scamps) and that they′d return after deafeat. Again and again and...
The Argonians were frenzied and the Daedra were sent into the Darkness, only to return and face the frenzied Argonians and be sent into the Darkness and...
That′s why they closed the gates to Black Marsh.
EDIT: ninja`d

Wow, the Argonians sound pretty amazing, actually! I wish I could see the Argonian counter-attack... Not in game, but where I can see the full scale.


Seriously, I didn't know the Argonians would be the ones who were the total badasses of the war! I was thinking Summerset Isles or Cyrodiil.

Damn, my opinion of them has changed completely.

I reckon the only reason why the Hist threw waves and waves of Argonians at the Daedra was just to save their own trunks. If the Argonians were pouring into the gates, what do think happened to the warriors already inside Oblivion? Probably slaughtered. I really don't think the Hist cared how many Argonians they sent to their doom, so long as they were safe.

Cyrodiil fared well since the CoC ran around shutting down gates everywhere. The Imperial City probably fared worse, but thankfully that assault didn't last. The Isles weren't so lucky. Crystal Tower came toppling down, and leadership disintegrated (Or were manipulated) to the point where the Thalmor could claim control.