The source of the conflict began in the early part of the 23rd century when official contact came between the Axanar and the Federation despite the fact that the Axanar had already encountered Humans over the previous years. At the time, the Axanar were seeking to expand their trading operations and mining rights to the planet Fabari. Fabari merchantmen and trade lines were continually harassed by Axanar starships with numerous incursions to their territory. In response to this, the Fabari petitioned for Federation membership and their aid in protecting them against the Axanar aggressors.
In turn to this, the Axanar would blockade Fabari and when a Starfleet vessel bearing a diplomat who would have negotiated a peace settlement arrived, the Axanar fired. This sparked of the Axanar war between the two governments which lasted for numerous months. However, victory was secured by Starfleet when Captain Garth of Izar won a crucial battle that brought about the Axanar's defeat. After their loss, the Axanar would sue for peace and reorganise their society as well as petition for Federation membership. (Decipher RPG module: Aliens)