A South Korean court has sentenced former President Yoon Suk Yeol to life in prison for his December 2024 attempt to impose martial law, in a landmark ruling that judges said was necessary to protect the country’s democracy.

“The defendant’s actions fundamentally damaged South Korea’s constitutional order and democratic values,” the presiding judge told a packed courtroom in Seoul. “This sentence reflects the gravity of attempting to subvert democratic governance through military force.”

Yoon, who was impeached and removed from office earlier this year, showed no visible reaction as the sentence was read. His legal team immediately announced plans to appeal.

The martial law crisis, which lasted only hours before being reversed by the National Assembly, sent shockwaves through South Korean society and strained the country’s alliance with the United States.

Thousands of supporters and opponents of Yoon gathered outside the courthouse, separated by heavy police presence. The ruling is expected to have significant implications for South Korean politics ahead of upcoming elections.