Thirteenth Legion

The Thirteenth Legion (also known as the Lost Legion) is an ancient group of Autobots.

Fiction

The Transformers cartoon

The Thirteenth Legion abandoned Cybertron after the wars that consumed the planet. They settled on the planet Antilla where they formed a thriving community with advanced technology.

The colony continued peacefully for some time until an asteroid shower impacted the planet and infected the Autobot colonists with Cosmic Rust. Unable to discover a cure despite their advanced technology, the colonists all died. One colonist managed to leave a recorded message to warn any visitors. Cosmic Rust

Knights of Unicron

The Thirteenth Legion Outpost, located on Planet Antilla, was the twentieth venue for the Knights of Unicron on their 2014 "Till All Are One" tour. Knights of Unicron

Notes

• The written language of Antilla is Ancient Autobot, a dialect no longer understood by modern Transformers. This, (combined with other factors) places the Thirteenth Legion's break with Cybertron between 11 million years ago and 9 million years ago.
• The Thirteenth Legion could be a reference to the Ninth Legion, also known as "The Lost Legion".