Sanctuary II

The Sanctuary II is a massive warship commanded by Thanos.

Massacre of the Zehoberei
When Thanos' forces invaded Zen-Whoberi, the Sanctuary II hovered above the capital city.

Intercepting the Asgardians
The Sanctuary II tracked down the Statesman carrying the Asgardian survivors of Ragnarök. On their way to Earth, Thor and Loki witnessed the Sanctuary II approaching them.

Attack on the Statesman
With the help of the Black Order and the Power Stone, Thanos was able to slaughter half of the Asgardians on the Statesman and add the Space Stone into the Infinity Gauntlet. Despite Heimdall and Loki being killed in the ordeal, Thor, Hulk, Valkyrie and a handful of Asgardians were able to escape.

Sacrifice of Gamora
After Thanos obtained the Reality Stone and kidnapped Gamora on Knowhere, he used the Space Stone to teleport both of them to the Sanctuary II. While in the ship's throne room, Thanos revealed to Gamora that he knew all along that she learned the location of the Soul Stone years ago. Having captured Nebula when she snuck aboard the Sanctuary II some time ago to kill him, Thanos used the Infinity Gauntlet to torture her until Gamora confessed that the Soul Stone was on Vormir to save her adoptive sister.

After Thanos and Gamora went to Vormir to obtain the Soul Stone, a Chitauri reassembled Nebula's cybernetics and was killed when she faked a malfunction and took it by surprise. After escaping from her captivity, Nebula contacted Mantis and requested that she and the rest of the Guardians of the Galaxy meet her on Titan, knowing that the members of Thanos' Black Order would meet him there once they found the Time Stone and Mind Stone. Nebula then took a Necrocraft and left the Sanctuary II to meet her allies on Titan.