Fidel Castro, the controversial Communist leader of Cuba, passed away on Friday, November 26. He was 90 years old.

His death was announced by his brother, Raul Castro, the current leader of Cuba, on Cuban state television, where a period of official mourning was declared until December 4, when Castro's ashed will be laid to rest in Santiago.

"The commander in chief of the Cuban revolution died at 22:29 hours this evening," Castro told the people of Cuba during the somber announcement. "Towards victory, always!"

In 1959, Castro swooped in to topple the Cuban government, introducing a Communist revolution and quickly becoming an adversary of the United States during the Cold War. His rule became the longest of any other living national leader aside from Queen Elizabeth II, lasting from 1959 to 2006, when he ceded most of his power to his brother after falling ill. He formally resigned as president in 2008.

Below, celebrities, pundits and politicians react to the news of Castro's passing across social media:

Famous Folks We Lost in 2016: