Side 4 was a colony cluster at Lagrangian Point L1. Being the cluster closest to the Principality of Zeon home Side 3, it was among the first to be attacked by Zeon during the One Year War and was hit hardest.
The Zeon assault left large amounts of debris that created a shoal zone with frequent electrical discharges, hence it was named the Thunderbolt Sector.
The cluster shared the Lagrangian Point with Side 8.
- Frontier I
- Frontier II
- Frontier IV
- New Manhattan
Side 4’s proximity to the Principality of Zeon home of Side 3 made it definite target. It was among the first Earth Federation territories to be struck by Zeon’s surprise attacks at the start of the One Year War. Side 4 sustained extensive damage as a result.
The cluster was rebuilt into the Frontier Side in UC 0120. Frontier I was the first colony to be constructed. Federation test ship Space Ark sought refuge at the colony when the Crossbone Vanguard invaded the Frontier Side in UC 0123.
Frontier IV was the first colony to be attacked by the Crossbone Vanguard. The Crossbone Vanguard seized Frontier VI and made it the capital of their new nation, Cosmo Babylonia. Frontier IV was renamed Cosmo Babylonia. Later in the war, the Crossbone Vanguard tested their new weapons at Frontier I, killing many civilians.
Civil war broke out in Cosmo Babylonia in UC 0125. When the nation collapsed in UC 0128, the Federation regained control of the Frontier colonies. The Cosmo Babylonia colony was once again called Frontier IV.
Settlement Freedom League
In UC 0218, the Federation collapsed and Side 4 became a member of the Settlement Freedom League. In UC 0223, the New Manhattan colony was used by the Illuminati resistance group as their headquarters.