Ciri's TIE Advanced x1, formerly used by Darth Vader, during run in the trench
The Battle of Yavin was a major battle of the Viau Universe's Civil War that led to the destruction of the first Death Star with Sera into being a fully-fledged fighter pilot, alongside Luke Skywalker's first step to becoming a Jedi when the battle occurred in the year 0 BBY (1415 NE). It was one of first major victories that the Rebel Alliance desperately needed to start a war against the Empire. With the imminent completion of the Galactic Empire's Death Star, the Alliance anticipated a major Imperial offensive. To unify command and coordinate a defense, the Mon Calamari Star Cruiser Independence carried members of the Alliance High Command to their base on Viau Yavin 4. Upon arrival, the Independence sent 70 squadron groups to the Yavin Base. Their numbers were augmented by veteran pilots as the Alliance gathered its resources in preparation for the coming battle.
While there was a space battle there was also a ground battle upon the planet Yavin 4 as the newly reorganized New Republic base was attacked by a combined taskforce made up of a number of the Axis members, the base was about to be breached until the arrival of the demon of the round table (Cipher) and Renegade squadron along with reinforcements sent by the Independence.