In an historic ruling, South Korea's Constitutional Court has formally removed impeached President Park Geun-hye from office over a corruption scandal that has plunged the country into political turmoil, worsened an already-serious national divide and led to calls for sweeping reforms.

Key points: Park Geun-hye faces possible criminal proceedings, first South Korean president forced from office

Park Geun-hye faces possible criminal proceedings, first South Korean president forced from office Fears that Ms Park's impeacment could spark violence between supporters and opponents

Fears that Ms Park's impeacment could spark violence between supporters and opponents Weeks of rallies involving millions of protesters created huge pressure on Ms Park

It was a stunning fall for Ms Park, the daughter of a dictator who rode a lingering conservative nostalgia for her father to a big win in 2012, only to see her presidency descend into scandal.

Park Geun-hye's downfall: July 27, 2016: A TV news report kicks off a series of media exposés ultimately revealing that Park's longtime friend, Choi Soon-sil, received classified government information such as drafts of presidential speeches.

July 27, 2016: A TV news report kicks off a series of media exposés ultimately revealing that Park's longtime friend, Choi Soon-sil, received classified government information such as drafts of presidential speeches. October 25: Park publicly acknowledges her close ties with Choi, and says Choi helped her on speeches and public relations issues during her 2012 presidential campaign and after her 2013 inauguration.

October 25: Park publicly acknowledges her close ties with Choi, and says Choi helped her on speeches and public relations issues during her 2012 presidential campaign and after her 2013 inauguration. October 27: State prosecutors launch a special investigation team to look into the scandal.

October 27: State prosecutors launch a special investigation team to look into the scandal. October 29: The first of what becomes a series of large anti-Park rallies is held in Seoul.

October 29: The first of what becomes a series of large anti-Park rallies is held in Seoul. October 30: Choi returns to South Korea from Germany and tells reporters two days later she "committed a sin that deserves death." on he way to the prosecutor's office.

October 30: Choi returns to South Korea from Germany and tells reporters two days later she "committed a sin that deserves death." on he way to the prosecutor's office. November 20: In indicting two former Park aides and Choi, state prosecutors say they believe the president was "collusively involved" in criminal activities by the suspects, who allegedly bullied companies into giving tens of millions of dollars to foundations and businesses Choi controlled and enabled Choi to interfere with state affairs. Park's lawyer calls the accusations groundless.

November 20: In indicting two former Park aides and Choi, state prosecutors say they believe the president was "collusively involved" in criminal activities by the suspects, who allegedly bullied companies into giving tens of millions of dollars to foundations and businesses Choi controlled and enabled Choi to interfere with state affairs. Park's lawyer calls the accusations groundless. December 3: Opposition lawmakers formally launch an attempt to impeach Park, setting up a floor vote. Massive crowds said to number more than 2 million demonstrate across the nation calling for Park's ouster.

December 3: Opposition lawmakers formally launch an attempt to impeach Park, setting up a floor vote. Massive crowds said to number more than 2 million demonstrate across the nation calling for Park's ouster. December 9: Lawmakers pass the impeachment bill on Park by a vote of 234 for and 56 opposed. The Constitutional Court begins preparations for Park's impeachment trial.

December 9: Lawmakers pass the impeachment bill on Park by a vote of 234 for and 56 opposed. The Constitutional Court begins preparations for Park's impeachment trial. January 5: The Constitutional Court begins hearing arguments in Park's trial. One of Park's lawyers compares her impeachment to the "unjust" deaths of Jesus Christ and ancient Greek thinker Socrates.

January 5: The Constitutional Court begins hearing arguments in Park's trial. One of Park's lawyers compares her impeachment to the "unjust" deaths of Jesus Christ and ancient Greek thinker Socrates. January 25: A former culture minister tells court Park's office blacklisted thousands of artists deemed unfriendly to her government with an intention to deny them state support.

January 25: A former culture minister tells court Park's office blacklisted thousands of artists deemed unfriendly to her government with an intention to deny them state support. February 17: Lee Jae-yong, the billionaire scion of Samsung, South Korea's largest business group, is arrested over suspicions that he bribed Park and Choi in exchange for business favours.

February 17: Lee Jae-yong, the billionaire scion of Samsung, South Korea's largest business group, is arrested over suspicions that he bribed Park and Choi in exchange for business favours. February 22: One of Park's lawyers tells court there will be a "rebellion and blood will drench the asphalt" if the court unseats Park and she is later acquitted of her charges through a criminal proceeding. Court closes arguments five days later.

The unanimous ruling opens her up to possible criminal proceedings, and makes her South Korea's first democratically elected leader to be removed early from office since democracy in the country in the late 1980s.

The court's acting chief judge, Lee Jung-mi, said Ms Park had violated the constitution and law "throughout her term", and despite the objections of parliament and the press, she had concealed the truth and cracked down on critics.

"The removal of the claimee from office is overwhelmingly to the benefit of the protection of the constitution ... We remove President Park Geun-hye from office," Ms Lee told the hearing.

Ms Park denied any wrongdoing.

South Korea must now hold an election within two months to choose Ms Park's successor.

Liberal Moon Jae-in, who lost to Ms Park in the 2012 election, currently enjoys a comfortable lead in opinion surveys.

Whoever becomes the next leader will take over a country facing a hostile North Korea, a stagnant economy and deep social and political divides.

Pre-verdict surveys showed that 70 to 80 percent of South Koreans had wanted the court to approve Ms Park's impeachment. But there have been worries that her ouster would further polarise the country and cause violence between her supporters and opponents.

Ms Park's parliamentary impeachment in December came after weeks of Saturday rallies that drew millions who wanted her resignation.

Overwhelmed by the biggest rallies in decades, the voices of Ms Park supporters were largely ignored. But they recently regrouped and have staged fierce pro-Park rallies since.

People on both sides have threatened not to accept a Constitutional Court decision that they disagree with.

One of Ms Park's lawyers told the court last month that there will be "a rebellion and blood will drench the asphalt" if Ms Park is booted from office.

Many participants at anti-Park rallies had said they would stage a "revolution" if the court rejected her impeachment.

"If Park accepts the ruling and soothes those who opposed her impeachment, things will be quiet," said Yoon Tae-Ryong, a political scientist at Seoul's Konkuk University.

"But looking at what she's done so far, I think that might be wishful thinking."

Others disagreed, saying violent protests won't be supported by the general public.

Protests after verdict

Hundreds of demonstrators, both for and against Ms Park, gathered outside the court, which was blockaded by police buses.

After the verdict, Ms Park's supporters and police scuffled at a demonstration outside the court — where two people died.

Police said one 72-year-old man was taken to hospital with a head injury and died, while the he circumstances of the second death were being investigated. Six people were injured, protest organisers said.

Elsewhere in the city, people welcomed her ouster.

A man on his knees looks up to the sky in happiness at a rally celebrating the impeachment of Park Geun-hye. ( Reuters: Kim Hong-Ji )

The main thoroughfare running through downtown Seoul was blockaded after the court's decision in anticipation of growing protests later in the day.

Prosecutors named Ms Park, who now loses her presidential immunity from prosecution, as an accomplice in two court cases linked to the scandal, suggesting she is likely to be investigated and could face legal proceedings.

Ms Park, 65, was been accused of colluding with her friend, Choi and a former presidential aide, both of whom have been on trial, to pressure big businesses to donate to two foundations set up to back her policy initiatives.

The court said Ms Park had "completely hidden the fact of [Choi's] interference with state affairs".

Ms Park was also accused of soliciting bribes from the head of the Samsung Group for government favours, including backing a merger of two Samsung affiliates in 2015 that was seen as supporting the succession of control over the country's largest "chaebol" — or family owned — conglomerate.

Samsung Group leader Jay Y Lee has been accused of bribery and embezzlement in connection with the scandal and is in detention — his trial began on Thursday.

Not everyone is happy about the impeachment — supporters of Ms Park staged large protests against the ruling. ( AP: Ahn Young-joon )

Prime Minister Hwang Kyo-ahn was appointed acting president and will remain in that post until the election.

If Hwang resigns, as some media have speculated he may to run for president, the finance minister will take over as acting president.

Park Geun-hye refused to testify in the impeachment trial. ( Wikimedia Commons: Korean Culture and Information Service )

AP