User blog comment:Jimeee/Elder Scrolls Online: Introduction to the Lore/@comment-4858067-20120825115017/@comment-4553238-20120825120738

well it is more of an agreement than an alliance against foreign forces such as the akaviri which attacked skyrim and the dunmer offered a pact of agreement and the nords needed the military force so they agreed and as tamriel was going to war with itself alot of wars were fought in black marsh so argonians allied with nords because of possibly differences between argonians and kahjiit at the time