Great Calamity

The refers to two distant events in Hyrule's history related to the resurgence of the Calamity Ganon in.

History
The Great Calamity was a period of mass destruction in Hyrule caused by the return of Calamity Ganon after being imprisoned for 10,000 years. This event led to many deaths and almost every structure across Hyrule to crumble into ruins. Hyrule Castle itself fell under Ganon and King Rhoam's life was ended. With Hyrule Castle having fallen and the army of Hyrule with no leader, they fell back to the fortress that protected Akkala, which also fell and was later known as the Akkala Citadel Ruins. The Great Calamity caused a great split within the Sheikah tribe, as a separate tribe known as the Yiga Clan grew and fought in allegiance to Calamity Ganon. Due to the Great Calamity, Hyrule experiences an increase in monsters. It also caused Stalkoblins, Stalmoblins, and Stalizalfos to appear at night.

Calamity Ganon achieved much of the destruction by possessing the Guardians and the Divine Beasts, ancient machines created by the Sheikah Tribe to defeat Ganon 10,000 years ago. Calamity Ganon successfully ended the lives of the Champions Daruk, Urbosa, Revali, and Mipha. Out of the Champions, only Link survived the Great Calamity, but was placed to slumber for 100 years within the Shrine of Resurrection after being injured while defending Princess Zelda. To prevent the destruction of the entirety of Hyrule and all its people, Zelda spends the 100 years after the Great Calamity inside Hyrule Castle with Calamity Ganon, keeping the demon in place within the Castle.