The Destruction of Aeten II took place in 3 ABY, shortly following the Battle of Hoth. Imperial Grand Admiral Martio Batch used the superlaser of the Empire's still-under-construction Tarkin superweapon to shatter the planet of Aeten II, releasing million's of the planet's stygium crystals into free-floating space, which Batch used to recreate the stygium screen cloaking device, technology that had all been lost to the galaxy.
Sources[]
"Who's Who: Imperial Grand Admirals" — Star Wars Insider 66
- The New Essential Chronology
- The Complete Star Wars Encyclopedia, Vol. III ("stygium crystal")
- The Essential Atlas
- The Essential Guide to Warfare