On 7 July 2884 SEY, a Vanduul Clan led by a Kingship launched a surprise attack on the moderately-populated planet Crion (Caliban II). The 89th UEE Navy Logistic Support Squadron were the only military forces in system at the time of the attack. They managed to hold off the Vanduul for two days, allowing much of the planet's population to escape at the cost of nearly the entire squadron. Naval reinforcements arrived on the third day to engage the full Vanduul fleet, but they were unable to hold out against the onslaught. On 23 July 2884, after heavy casualties, Crion and the rest of the Caliban system were lost to the Vanduul. In honor of their sacrifice, the 89th Squadron was retired, earning them the nickname "the Lost Squad." This battle marked the last time a Kingship was spotted by United Empire of Earth (UEE) forces until the Battle of Vega II in 2945.

Small Vanduul raiding parties first began attacking Caliban in 2739, during the latter years of the Messer era (2546 - 2792). While the initial raid sparked fear in the system's inhabitants, causing a brief population drain, the skirmishes were largely casualty-free. As raids continued to occur at a steady rate of between two and five per year, the UEE installed a small naval presence along with system-wide perimeter sensors. The people of Crion saw this response as inadequate; political activism spiked among the populace, but the Messers sent no more aid.

During the fall of the Messer regime in 2792, the military presence in Caliban was pulled away from the system to repress mass civilian uprisings elsewhere. A medium-sized Vanduul Clan launched a raid on the largely undefended system, which claimed over one hundred lives. The newly formed post-Messer UEE government ordered the 31st Battle Group to Caliban to fend off the invasion. Their efforts were successful in stopping the raid from spiraling into something much deadlier.

Subsequent Vanduul raids dropped down to previously established levels of roughly five per year, finally peaking in 2859 when a single large Clan clashed with the 31st Battle Group in the system's asteroid belt. This was the last Vanduul raid until 2884. By 2870, the 89th Logistics Support Squadron was Caliban's only protection.

At 04:43 Earth Standard time (UST), 7 July 2884, a Vanduul Clan led by a Kingship slipped past the system-wide sensor beacons. Two pilots of the 89th, on patrol near Caliban IV, spotted the Clan. Both of them fired off a distress signal, but their messages were cut off before they could be completed.

Not comprehending the scope of the threat they faced, the bulk of the 89th mobilized against the invading Clan. Four ships were lost to advancing scouts before the Kingship was in sight. At the sight of it, CO Commander Sylvie Randall made two snap decisions; first, to send out comm drones requesting reinforcements, knowing that it might take up to two days for reinforcements to arrive; second, to retreat back to Crion to organize and defend civilian convoys. It was this decision that allowed over three million inhabitants to escape with their lives.

By the time the 2nd UEE Naval Fleet arrived, 49 SE Hours later, there was nothing left to do but rescue any remaining people and abandon the system. The 89th Squadron, along with the Caliban system, were lost. It is estimated that over five and a half million people died, though no official numbers have ever been released.

No attempts were immediately made to reclaim Caliban. Though the Kingship responsible for the bulk of casualties in battle returned to Vanduul space soon after its victory, UEE forces held off on moving in until casualties could be assessed. The UEE announced in 2891 that there were no active plans to retake Caliban until the Vanduul threat could be fully neutralized. In 2945, military strategists began to discuss possible future campaigns into the system to rout the Vanduul encampments.

Historians believe that the decades of Vanduul absence in Caliban, combined with a thinly-spread military, poor system-wide sensor maintenance, and an incomplete understanding of Vanduul intentions were what led to the invaders' decisive victory. Though the Tiber, Virgil, and Orion systems had already been abandoned to the Vanduul, military strategists did not foresee an attack of that strength on Caliban. The 89th Squadron was there in full force, but one squadron was not enough to stand against the firepower of a Kingship. In honor of their sacrifice, Squadron 89, redubbed the Lost Squadron, was officially retired from the UEE Navy.

Vanduul Harvesters are actively consuming what is left of the Caliban system. Crion, once a thriving, lush world, is now devastated. There are no known Human inhabitants in the system.