Why was the Imperial Legion so effective at stopping Mehrunes Dagon from destroying the Imperial City?

by [deleted]

And is there any kernal of truth to the myths of a Hero of Kavatch or Akatosh saving the city?

Krateng

Finding out the truth about single heroes is usually very hard. While there are accounts of this hero of Kvatch, it seems strange that not even their species or gender is ever mentioned. It is most likely an invented figure to boost troop morale.

Sources:

The lusty Argonian Maid

Mysterium Xarxes'

Decoration Guide (Breezehome)