Praxus

Praxus is one of Cybertron's city-states, located in the northern hemisphere. It borders one or more of the following city-states: Altihex, Iacon, Kalis, Tyger Pax, and Nova Cronum, making it one of the city-states the Tri-Torus Loop leads to. Praxus is Cybertron's technological and cultural center and occupies a prominent position in Cybertron's political arena. This tends to put the citizens at odds with the Decepticons, who seek to forcefully reimagine Cybertronian society. For this reason, Praxus often is targeted during the war.

Exodus

 * Locations
 * The Assembly
 * The Helix Gardens

Praxus was a progressive state, its Helix Gardens a symbol of the Golden Age, and its Assembly was where scientists of Crystal City and Nova Cronum presented their findings. Many of its citizens approved of Megatron's anti-caste system beliefs, but were disappointed by his militant direction. Megatron felt betrayed by this reaction, and so he sent Seekers, Constructicons and Bruticus Maximus to attack. The Praxians threw in their support with the Autobots. With Praxus far from primary Decepticon territory, Megatron ran into the same supply problems as the Autobots normally did, and Praxus became the war's first stalemate. With thousands dead and the city ruined, Megatron conceded defeat and his soldiers left.

It was at Praxus that Optimus Prime gained two indispensable allies in Ironhide and Prowl. It was also the place where Ratchet made his name as medic and soldier.

Shattered Glass
When Astrotrain had attached himself to the hull of the Ark and was destroying the ship's guns along with his Micromaster squad, Rodimus compared them to Praxian mech-ticks and suggested they'd deal with them the same way; by burning them off. There's also a place called Praxus-Delta, but the nature of its supposed connection to Praxus is unknown.