The Tydirium was a Sienar Fleet Systems Imperial Lambda-class shuttle, which operated as a courier and a transport in the Prefsbelt system. It was later present at Outpost 327 over Zhar, where it was captured by General Crix Madine of the Alliance of Nations. Madine hoped to use the shuttle and the clearance codes it carried to have a strike team infiltrate the Forest Moon of Endor, around which orbited a new Imperial battlestation, the second Death Star. The strike team would then, if all went as planned, deactivate the deflector shield protecting the still-under-construction Death Star.
Despite this effort, the ship itself later fell into Imperial hands, and was held at the Prefsbelt Naval Academy on Prefsbelt IV. With Madine once again coordinating the operation, the shuttle was once again stolen, this time by pilot Wedge Antilles. The Tydirium was then used by General Han Solo and his strike team to infiltrate the moon of Endor, as planned. His mission to deactivate the deflector shield was coordinated by General Brenn Tantor, who stayed aboard the Tydirium while the rest of the team ventured out onto the moon. Following the Great Battle of Endor, in which the Death Star II was destroyed, Solo used the Tydirium to capture the Nomad Star Destroyer Accuser.