Seoul, Apr 4 (AP) Yoon Suk Yeol's political rise was fast: the former star prosecutor clinched South Korea's presidency only a year after he entered politics.

But his downfall was even faster: The Constitutional Court removed him from office on Friday, about four months after he made a deeply baffling decision to declare martial law and send troops to Seoul's streets.

Yoon's style — highly assertive and strong-willed, but often uncompromising and inflexible — worked for a prosecutor standing up to higher-ups, but not for a president forced to work with an opposition-dominated legislature on an array of contentious issues.

Yoon, 64, a conservative, said his martial law decree was a desperate attempt to call on public support for his fight against “anti-state” liberal rivals who used their parliamentary majority to obstruct his agenda and impeach top officials. But many observers say the stunt was political suicide, as the liberal opposition-controlled parliament quickly struck down Yoon's decree before impeaching him and sending his case to the Constitutional Court. ' Yoon was separately indicted by prosecutors for rebellion, a charge that can carry the death penalty or life imprisonment.

Here's what you need to know about Yoon's life to understand the sudden end of his presidency.

A popular prosecutor Before becoming president in 2022, Yoon worked as prosecutor for about 26 years, establishing an image as a strong-minded, uncompromising prosecutor who didn't yield to pressure from powerful figures.

Yoon rose to stardom in 2013, when he publicly accused his boss of pressuring him to drop a high-stakes investigations into allegations that the state intelligence agency had carried out an illegal online campaign to help conservative Park Geun-hye win the previous year's presidential election.

During a hearing at parliament, Yoon famously said, “I'm not loyal to (high-level) people.” He was demoted, but after Park's government was toppled over a separate corruption scandal in 2017, liberal President Moon Jae-in made Yoon head of a Seoul prosecutors' office that investigated Park and other conservative leaders. Yoon was later appointed as Moon's prosecutor general.

Political rookie of the year In 2021, Yoon left the Moon administration and entered politics following disputes over probes of Moon allies. Moon's supporters accused Yoon of attempting to frustrate Moon's push to reform the Korean prosecution service and boost his political standing. Yoon, for his part, called the Moon government “corrupt,” “incompetent” and “arrogant.” Yoon joined then the opposition People Power Party, the country's biggest conservative party, whose leaders he previously investigated, as it was looking to embrace a popular outside figure to lead its fight to regain power in the following year's presidential election.

In 2022, in his first national election campaign, Yoon defeated Democratic Party candidate Lee Jae-myung in the country's most closely fought presidential election.

The election race got nasty, with Yoon describing Lee's party as “Hitler” and “Mussolini” while an associate called Lee's purported aides “parasites.” Lee's allies called Yoon “a beast,” “dictator” and “an empty can” and derided his wife over claims she had had plastic surgery.

A turbulent presidency On foreign policy, Yoon was credited with working hard to reinforce South Korea's military alliance with the U.S. and repairing disputes with Japan over historical traumas to build a stronger trilateral security partnership to cope with North Korea's advancing nuclear program.

In April 2023, Yoon charmed a White House state dinner by singing “American Pie" at the request of then-President Joe Biden. In August 2023, Yoon, Biden and Japan's then-Prime Minister Fumio Kishida met at Camp David in their countries' first stand-alone trilateral summit, where they agreed to bolster defense cooperation. Yoon and Kishida revived stalled high-level talks and withdrew reciprocal economic restrictions imposed under their predecessors.

But domestically, Yoon's time in office was marred by near-constant political strife with Lee's party, unprecedented even in South Korea's deeply polarized political world.

With control of the National Assembly, the Democratic Party filed a total of 30 impeachment motions against senior officials. None has yet been upheld by the Constitutional Court, except that of Yoon. The Yoon administration vetoed opposition-led bills about 40 times.

Eventually, Yoon tried to break through the gridlock by declaring martial law. He says that it was an attempt to appeal for the public's help to overcome the “wickedness” of the Democratic Party. Critics say he was simply aiming to use force to impose his will on the legislature.

In his martial law announcement, Yoon called the Democratic Party-led assembly “a den of criminals,” “a monster” and “anti-state forces.” Democratic Party leaders lambasted Yoon's martial law, calling him “an alcoholic,” “a madman” and “ringleader of a rebellion.” Wife hit by scandals Some observers say the martial law decree was more likely driven by Yoon's hopes to frustrate an opposition-led bid to open a special investigation into allegations involving his wife, Kim Keon Hee.

Kim's allegations include spy camera footage showing the first lady accepting a luxury bags as a gift from a pastor; speculation she was involved in a stock price manipulation scheme; and revelations that she, along with Yoon, exerted inappropriate influence on the People Power Party to pick a candidate to run for a parliamentary by-election in 2022.

Kim's scandals and Yoon's refusal to apologize and accept investigations provided the Democratic Party political ammunition throughout his term. (AP) AMS