The Autobots are a military group devoted to defending their planet, and the innocents of other worlds, including Earth, from the would-be conquest of the Decepticons. For millions of years they were the underdogs of the war, barely holding their ground through sheer temerity and perseverance. In the aftermath of Unicron's attack in 2005, they were able to take advantage of the confusion on Cybertron to reclaim most of the planet, and now oppose the Decepticons on roughly equal footing. The Autobots are also allied with the government of Earth, and many of them consider the Terran planet a second home.