The Sword of the Jedi was a title bestowed upon Jaina Solo during the Yuuzhan Vong invasion of the galaxy. Luke Skywalker, the Master of the Jedi Order and Jaina's maternal uncle, gave his niece this name upon her knighting.
Jedi Master Skywalker referred to Jaina, during the initiation ceremony, as "...a burning brand to your enemies, a brilliant fire to your friends." The comment struck Jaina deeply as she had been finding it increasingly difficult to function during the war and had been distancing herself from her friends and family.
However, not even Skywalker was entirely sure what being the Sword of the Jedi entailed. For the rest of the Yuuzhan Vong War and beyond Jaina struggled to understand what being the Sword of the Jedi meant, what she had to do to fulfill her destiny, and how it would affect her life.
The answer came during the Second Galactic Civil War when Jaina's brother Jacen Solo fell to the dark side, becoming Darth Caedus and took over the Galactic Alliance. With Skywalker unable to face Caedus, for fear of falling to the dark side himself to avenge his wife, the burden fell to Jaina. Only after killing her brother, saving the galaxy from him but also changing everything between her and her family, did Jaina feel she had finally become the Sword she was meant to be.
- Fate of the Jedi: Dramatis Personae