The Battle of Yavin IV was a key battle during the Zao tenj War. Part of a desperate move from the Jedi/Sith alliance, the battle of Yavin IV was the first time Darth Nihilus had allied himself with the Jedi.
Although the victory did little to dent the Zao tenj's hold in the sector, it did succeed in boosting the morale of the Alliance's population. It also succeeded, however, in showing the Zao tenj that the Jedi and the Sith were far from at each other's throats, and that this was something to be rectified.