South Korean President Yoon Suk Yeol, who declared martial law on Tuesday, was elected in 2022 as a conservative political novice promising a tougher line on North Korea.
He has not had an easy ride, taking office with some of the lowest approval ratings of any democratically elected South Korean president.
Those ratings dropped even further to 19 percent in the latest Gallup poll last week, with many expressing dissatisfaction over his handling of the economy and controversies involving his wife, Kim Keon Hee.
In declaring martial law the South Korean leader accused the opposition of being "anti-state forces" and said he was acting to protect the country from "threats" posed by the North.
Observers and allies have been left scrambling to make sense of the sudden move.
Born in Seoul in 1960, Yoon studied law and went on to become a star public prosecutor and anti-corruption crusader, playing an instrumental role in former president Park Geun-hye being convicted of abuse of power.
As the country's top prosecutor in 2019, he also indicted a top aide of outgoing president Moon Jae-in in a fraud and bribery case that tarnished that administration's image.
The conservative People Power Party (PPP), in opposition at the time, liked what they saw and convinced Yoon to become their presidential candidate.
He duly won in March 2022, beating Lee Jae-myung of the Democratic Party, but by the narrowest margin in South Korean history.
Yoon was never much loved, and a series of scandals -- including his administration's handling of a deadly Halloween crush of 2022 -- have further eroded his popularity.
Critics have blamed Yoon's administration for food inflation, a lagging economy, and increasing constraints on freedom of speech.
He was also accused of abusing presidential vetoes, notably to strike down a bill that would have paved the way for a special investigation into his wife's alleged involvement in stock manipulation.
Yoon suffered further reputational damage last year when his wife was secretly filmed accepting a designer handbag worth $2,000 as a gift. Yoon insisted it would have been rude to refuse.
His mother-in-law, Choi Eun-soon, is serving a one-year prison sentence for forging financial documents in a real estate deal. She is due to be released in July.
Yoon was earlier this year the subject of a petition calling for his impeachment, which proved so popular the parliamentary website hosting it experienced delays and crashes.
Local media have reported that Yoon is particularly inspired by British wartime prime minister Winston Churchill.
As president, Yoon has maintained a tough stance against Pyongyang and bolstered ties with Seoul's traditional ally, the United States.
Last year, he famously sang Don McLean's "American Pie" during his visit to the White House, to which US President Joe Biden responded, "I had no damn idea you could sing."
But his efforts to restore ties with South Korea's former colonial ruler, Japan, did not sit well with many at home, as the issue remains sensitive in the country.
The return of former US president Donald Trump -- who had historic but ultimately failed summits with North Korea's leader Kim Jong Un while in office -- may create another layer of tension, experts say.
