The Allied Forces came together following the occupation of the Kingdom of Obel by the Kooluk Empire. The giant Headquarters Ship which had escaped the Obel occupation as well as its leader, was able to gather together disparate forces from across the region, forming an alliance that was able to fight back against the Kooluk advance.
This war would eventually come to an end with a final battle at the Kooluk southern base of El-Eal Fortress in SY 307. With Kooluk's naval forces broken and the fortress destroyed, a cease-fire was quickly negotiated, ending the war. With the foundation of the Island Nations Federation, the Federation navy would become the authorized military force for the fledgling nation.
The name Allied Forces (連合軍, Rengō-gun) is a generic descriptor used in Suikoden series publications as the name can actually be customized by the player or chosen from two different options, "the Rush" (suggested by Desmond) or named after the hero (as suggested by Akaghi).
- Genso Suikoden Kiwami Encyclopedia, page 403