President Yoon Suk Yeol bows during a televised address at his residence in Hannam-dong, Seoul, Saturday, after the National Assembly passed a motion to impeach him. Courtesy of presidential office

With the National Assembly's passage of a motion, Saturday, to impeach President Yoon Suk Yeol for his botched martial law attempt, the former star prosecutor-turned-politician became the third president in the nation's history to be stripped of his authority.

Impeached on charges of leading an insurrection, the 63-year-old, who ascended to the presidency vowing to uphold the law, now faces a review by the Constitutional Court to determine whether he will be removed from the nation's highest public office.

Yoon is under investigation for treason, and there is a possibility that he could be placed under emergency detention or formally arrested during the court review. If that happens, he will become the first sitting president to be imprisoned. Under the law, treason is punishable by life imprisonment or even death if convicted.

The former star prosecutor, known for his uncompromising and often stubborn stance, has left a significant stain on Korea's constitutional history, from his shocking Dec. 3 martial law declaration and allegations of ordering the military to suppress state institutions, including the National Assembly and the National Election Commission.

Yoon Suk Yeol, then-chief prosecutor of Suwon District Prosecutors' Office's Yeoju branch, heads to a podium to answer questions during the National Assembly's inspection of the prosecutor's office at the Seoul High Prosecutor's Office in this Oct. 21, 2013 file photo. He claimed that he was pressured to drop an investigation into allegations that the National Intelligence Service manipulated public opinion online to support then-President Park Geun-hye during the 2012 presidential election and his remarks made his name an upright prosecutor. Newsis

‘I am not loyal to anyone'

Born in 1960, Yoon began his career as a prosecutor in 1991 at the age of 31, after passing the bar exam on his 10th attempt.

He subsequently built an image as an "upright prosecutor" by leading investigations that didn't bow to political pressure under various administrations.

Yoon gained public recognition in 2013 when he led the prosecution's special investigation team amid allegations of interference by the National Intelligence Service in the 2012 presidential election.

As this case could have a profound impact on the legitimacy of the newly inaugurated President Park Geun-hye, the investigation attracted widespread national attention at that time.

However, Yoon, then chief prosecutor of the Yeoju branch of the Suwon District Prosecutors' Office, was removed from the investigation team for requesting arrest warrants without his superior's approval.

Later that year, during a parliamentary audit of the Seoul Central District Prosecutors' Office, he revealed that there had been external pressure on the investigation. He famously stated, "I am not loyal to any person, but loyal to the organization," a remark that solidified his name in the public's memory.

Consequently, he was sidelined from key prosecutorial positions, mostly holding positions where he rarely conducted criminal investigations.

However, he regained prominence in late 2016 when the corruption scandal involving Park erupted.

In November 2016, Yoon was appointed as the head of the special prosecutor's investigation team for the case, spearheading a thorough inquiry into government officials in the Park administration.

He garnered widespread public support for his impartial investigation, targeting not only government officials but also prominent figures such as Lee Jae-yong, the then-vice chairman of Samsung Electronics, for whom he sought an arrest warrant on bribery charges.

On March 10, 2017, the Constitutional Court finally removed Park from office for violating the Constitution, following the passage of her impeachment motion by the National Assembly.

In May, newly elected President Moon Jae-in appointed Yoon as chief prosecutor of the Seoul Central District Prosecutors' Office, and in July 2019, he was named prosecutor general of the Supreme Prosecutors' Office.

While Yoon initially thrived under that administration, his relationship with the president and his aides soured over investigations related to Cho Kuk, the justice minister and a close ally of Moon. Following conflicts with government officials, he resigned as prosecutor general in March 2021.

President-elect Yoon Suk Yeol performs his signature uppercut ceremony to supporters in Yeouido, Seoul, March 10, 2022, a day after the presidential election. Korea Times photo by Oh Dae-geun

Rising star

His conflicts with the liberal Moon administration garnered Yoon increasing support from conservative voters. On June 29, 2021, he officially announced his candidacy for the 20th presidential election and joined the opposition People Power Party (PPP) shortly thereafter.

Amid rising public dissatisfaction with Moon over soaring real estate prices and controversies surrounding influential figures, particularly allegations of college admission fraud involving Cho's children, Yoon emerged as a strong presidential contender with high approval ratings.

He went on to win the March 2022 presidential election by a narrow margin of 0.73 percentage point over main opposition Democratic Party of Korea (DPK) candidate Lee Jae-myung.

After his narrow victory, Yoon struggled to gain broad support as president due to persistent controversies.

Notable among these were allegations surrounding his wife, Kim Keon Hee, including receiving a Christian Dior bag from a pastor and involvement in stock price manipulation.

Entering the presidency with little political experience, Yoon's approach to governance was marked by a tendency to bypass the political establishment. His reluctance to engage with the opposition and his unyielding stance on certain issues gradually eroded his support.

In the April general elections this year, the ruling party won just 108 out of 300 seats at the National Assembly, including 18 gained through proportional representation by its satellite party, the People Future Party.

In contrast, the DPK secured an overwhelming 175 seats, effectively stripping the president of his ability to govern.

The president has since refused to concede, clinging to conspiracy theories that the election was rigged.

In response, the DPK passed impeachment motions against Cabinet members and special prosecutor probe bills into the first lady, while Yoon kept vetoing various draft legislations ratified by the opposition-led Assembly.

In an attempt to recover his dwindling political fortune, Yoon decided to declare martial law on the night of Dec. 3, which sent shockwaves across the globe. That declaration was quickly nullified by the National Assembly, leading to Yoon's impeachment 11 days later.

The president now faces looming legal battles over his impeachment at the Constitutional Court.