Responsible for forty percent of Cybertron's industrial output (which is really saying a lot) the Tagan Heights were considered one of the most strategically valuable regions of Cybertron. And during the Dark Ages, everyone wanted it real bad.
After the disappearance of Optimus Prime and Megatron during a test of the space bridge, the Autobots and the Decepticons split into different factions, each with different agendas and different areas of control, essentially rendering the Great War into a turf dispute. During this time, the Tagan Heights, with all its industrial manufacturing capabilities, became one of the most disputed regions on the planet. Ratbat and the Ultracons made several efforts to secure the Heights, only to be frequently thwarted by Springer and the Wreckers. Ratbat's frustration became so great that he openly defied the Crisis Intervention Accords and convinced the Constructicons to ally with the Ultracons. Ratbat subsequently unleashed Devastator in an attempt to take the Tagan Heights, but the Protectobots learned what was happening and went to battle Devastator as Defensor. During the battle between the two Combiners, much of the Tagan Heights was destroyed.