SEOUL -- South Korea's former President Yoon Suk-yeol on Tuesday filed an appeal against his life sentence for leading an insurrection relevant to his martial law declaration, according to Yonhap news agency.

Yoon's legal team submitted the notice of appeal to the Seoul Central District Court, which sentenced him to life in prison on charges of ringleading the insurrection.

By law, the insurrection ringleader can only be sentenced to capital punishment or life imprisonment if found guilty.

Yoon was accused of orchestrating the insurrection by declaring an unconstitutional emergency martial law despite the absence of war, incident, or equivalent national emergencies.

Yoon was also charged with mobilizing martial law troops and police to obstruct the National Assembly's resolution to lift the martial law and attempting to detain key political figures, such as the leaders of the main political parties and the parliamentary speaker.

The emergency martial law was declared by Yoon on the night of Dec. 3 in 2024, but it was revoked hours later by the National Assembly.

The constitutional court upheld a motion to impeach Yoon in April of 2025, officially removing him from office.

Yoon was indicted under detention in January of 2025 as a suspected ringleader of insurrection, becoming the first sitting president to be arrested and indicted.