Yoon Suk Yeol: South Korea's scandal-hit president who declared ...

Yoon’s presidency has been mired in scandal. Much of it centred around his wife Kim Keon Hee, who was accused of corruption and influence peddling - most notably allegedly accepting a Dior bag from a pastor.

In November, Yoon apologised on behalf of his wife while rejecting calls for an investigation into her activities.

But his presidential popularity remained wobbly. In early November, his approval ratings tumbled to 17%, a record low since he took office.

In April, the opposition Democratic Party won the parliamentary election by a landslide, dealing a crushing defeat for Yoon and his People Power Party.

Yoon was relegated to a lame duck president and reduced to vetoing bills passed by the opposition, a tactic that he used with “unprecedented frequency”, said Celeste Arrington, director of The George Washington University Institute for Korean Studies.

This week, the opposition slashed the budget the government and ruling party had put forward - and the budget bill cannot be vetoed.

Around the same time, the opposition was moving to impeach cabinet members, mainly the head of the government audit agency, for failing to investigate the first lady.

With political challenges pushing his back against the wall, Yoon went for the nuclear option - a move that few, if any, could have predicted.

“Many observers worried in recent weeks about a political crisis because of the confrontation between the president and the opposition-controlled National Assembly,” said Dr Arrington, “though few predicted such an extreme move as declaring martial law.”

President Yoon's declaration of martial law was a "legal overreach and a political miscalculation", according to Leif-Eric Easley, professor of international studies at Ewha Womans University in Seoul.

"With extremely low public support and without strong backing within his own party and administration, the president should have known how difficult it would be to implement his late-night decree," Dr Easley told the BBC.

"He sounded like a politician under siege, making a desperate move against mounting scandals, institutional obstruction, and calls for impeachment, all of which are now likely to intensify."