Former South Korean President Yoon Suk Yeol greets supporters in front of the Seoul Central District Court on Monday before hearing the indictment against him. He is currently charged with insurrection for his 18-day declaration of martial law last December.

South Korea’s Constitutional Court has unanimously removed Yoon Suk Yeol as president after he threw the nation into turmoil by declaring martial law and sending troops to parliament in an ill-fated effort to break through legislative gridlock.

South Korea's ousted leader Yoon Suk Yeol argued that his brief martial law declaration late last year was "not a coup d’etat" as he appeared in court on Monday for the start of a criminal trial over charges that he led an insurrection.