We know that the Akaviri (specifically the Tscaesci) have conducted several raids and invasions of Tamriel, with much success and ground gained. But how? How did invaders who had travelled across a (presumably) large sea manage to devastate so much of Skyrim and Morrowind? Surely the Nords and Dunmer would have been able to set up a decent defence in the own lands. They had so many environmental advantages, and yet the Akaviri managed to cut through Tamriel and rule Cyrodiil and the Empire for a time. Were the Akaviri led by the greatest military minds the world had ever known? Did they win through extreme numbers? Or was there something else at play?
I also find it curious how people from the far east managed to raid the Wayrest and the Illiac Bay so proficiently that Wayrest was besieged. They also conducted ray in the Niben. It's impressive to say the least that these people could sail from one continent to another, and then sail all the way around this massive continent and yet still maintain a highly effective martial prowess over the natives.
The Second Invasion, however, was far less one-sided, with the Nords, Dunmer and Argonian forces smashing the Akaviri at Stonefalls before Vivec devastated them with the sea. But that only emphasizes my original point, that the first brutal invasion by the inhabitants of Akavir was absurdly effective.