Invasion of Nidavellir

The Invasion of Nidavellir was a conquest of the Dwarven homeplanet of Nidavellir undertaken by the Troll Lords, sparked by the lack of peaceful influence of the Asgardians once the Bifrost Bridge was destroyed.

Background
Following the destruction of the Bifrost Bridge at the hands of Thor in the Duel at the Bifrost Bridge, the Asgardians were unable to intervene in attacks on the other Realms.

Invasion
The Troll Lords seized the opportunity of the Asgardian inability to travel in order to conquer Nidavellir, and started to force the Dwarves to work for them and make weapons for their future wars.

Aftermath
However, as the Tesseract was taken into Asgard's possession, On their return to Asgard, Loki was imprisoned in the Asgardian Dungeons and the Tesseract was given to Heimdall so that he could fix the bridge.

Thor commanded the Asgardian army to travel to Nidavellir and the rest of the worlds taken by force, and restore peace in them.