The Autobots are a group that have figured prominently in Union history. The group led by Optimus Prime from Transformers-1 has been in the Multiverse for over 400 years, near its inception, and other Autobot groups have joined them. Although there are "fringe" groups, and even a few that are their mirror opposite, Autobots are generally bound by a desire to preserve life whenever possible, defend the innocent and helpless, and carry a hatred of their opposite numbers, the Decepticons, with whom they have been at war with for many millions of years.
Variants and origins
As there are many, many Transformers variants, even within canon, and thousands within fanon and personal canon, so too are there many, many variants on the group known as the Autobots.
Began shortly after the end of the Quintesson invasion. The origins of this difference were found in the division of the race that the Quintessons placed on the Transformers, the war-like "military" grade slaves and the peaceful "civilian" grade slaves. The military line eventually tended more towards conquest, and the civilian line sought to prevent this, causing three major civil wars and thousands of minor conflicts over the past 20 million years, ensuring most of that time was spent in warfare between the two great armies in one form or another, which has impeded the progress of their society greatly.
Autobots in this universe are particularly noteworthy in that they are considerably less hesitant to use force against the Decepticons if need be than many of their breatheren, and rather quickly adapted to the military needs of their situation. Their fighting force easily matches the Decepticons and they are not afraid to use it - much to the rather fatal mistake of some other Decepticons ignorant to the dimensional differences between these Autobots and the natives they were used to. As a result, some Autobot groups have often accused them of being butchers and little better than the Decepticons - often before asking them for help to keep their own groups from extinction from Decepticon raids. A number of smaller Autobot groups that suffered from situations like this have been integrated into this group of Autobots since the Multiverse began.
Autobot holdings on the mega-Cybertron are somewhat tenuous, and are actually less than those of the Decepticons - however, this is highly deceptive in showing their position in the war. While in terms of surface area their influence is limited, Cybertron is a planet that is actually a massive structure, complete with deep, massive underhalls and caverns, and is many thousands of levels deep. These underground tunnels and catacombs are just as important to holding Cybertron and access to resources as the surface. The Autobots control a massive amount of this underground territory, giving them access to quite a few resource points, as well as general room for expansion. Many significant Autobot cities are nearly entirely, or outright entirely, underground, as a result, though their capital, the massive fortress-city Iacon, is primarily above ground.