Updated at 4:41 p.m. ET

He was his country's most powerful man. Time magazine crowned him "king of Israel." But he couldn't win over Israel's unforgiving free press. So he is accused of buyinghis way inside the newsroom of a leading news site, secretly dictating flattering coverage that helped him win reelection twice.

That allegation is at the center of an unprecedented courtroom drama that kicked off Sunday in Jerusalem: the State of Israel v. Benjamin Netanyahu.

The longest-serving prime minister in Israel's history, after 11 uninterrupted years in office, entered the courtroom charged with bribery, fraud and breach of trust. If convicted, he could spend several years behind bars.

It's the first time in Israel — and much of the world — that a sitting leader has gone on trial.Usually, senior Israeli officials step down when they face corruption charges, as did Netanyahu's predecessor, former Prime Minister Ehud Olmert.

But Netanyahu is not required by law to step down after being indicted and has refused to resign. The conservative leader denies wrongdoing and alleges there isa left-wing witch hunt against him, a claim that has sparked an ugly culture war against Israel's judiciary, law enforcement and media.

The saga plunged the country into political turmoil for more than 500 days. Israel held three national elections, each serving as a referendum on Netanyahu, but producing no clear winner. Finally this week, with Supreme Court approval, Netanyahu sealed a deal with his opposition rival and formed a new unity government.

"It's terrible. It's the first time that an acting prime minister is on trial, criminal trial, indicted by very, very serious offenses," said Emanuel Gross, professor emeritus of law at Haifa University. "This is a crucial moment."

What are the allegations against Netanyahu?

The most serious one carries the charge of bribery. Prosecutors accuse Netanyahu of offering regulatory favors worth hundreds of millions of dollars to a telecommunications executive, and in returngainingsecret editorial control over Walla! News, Israel's second biggest news site. For nearly five years, including during his 2013 and 2015 reelection campaigns, Netanyahu and his wife Sara allegedly made hundreds of editorial demands of the executive and his wife, placed stories and photos, killed unflattering coverage and wielded influence over the hiring of editors and reporters.

"Generally, in criminal charges of bribery, it's hard to have good evidence between the quid and the pro," said Amir Fuchs of the nonpartisan Israel Democracy Institute. "In the indictment, you see a lot of evidence of the link."

But it's not a classic bribery case where the interest is money or sex. Never before has an Israeli official been indicted of bribery for securing positive press.

Netanyahu also faces lesser charges of fraud and breach of trust in two other cases. He's accused of discussing a secret proposal with the owner of Israel's biggest news site, YNet, and its related paper Yediot Ahronot, to promote legislation undercutting the owner's biggest competitor in exchange for the owner reversing his critical editorial line against Netanyahu.

The prime minister is also accused of pulling strings with U.S. and Israeli officials to benefit a Hollywood producer who provided the Netanyahus with a constant supply of expensive jewelry, cigars and champagne. Netanyahu also accepted a regular supply of cigars and champagne from an Australian businessman.

What will the trial look like?

Two groups of demonstrators formed outside the prime minister's residence hours before Sunday's hearing. Separated by a line of police, anti-Netanyahu protesters faced off against supporters of the prime minister, who had been organized by his Likud party.

Netanyahu arrived at the district courthouse in East Jerusalem to appear before the three-judge panel on Sunday afternoon. Surrounded by members of his cabinet, the prime minister gave a 15-minute long televised speech before entering the courtroom.

In his defiant address, Netanyahu alleged a conspiracy by the attorney general, justice officials, police investigators, the left wing and the media

"What is on trial today is the attempt to thwart the will of the people - to topple me and topple the right wing," Netanyahu said.

During the 45-minute long hearing, supporters continued to chant messages over loudspeakers right outside the courtroom window. Inside the courtroom, the head judge asked Netanyahu's lawyer to step aside, multiple times, to get a view of the prime minister sitting behind the bench.

Netanyahu did not enter a plea on Sunday.

The telecom executive and his wife and the newspaper owner also face bribery charges.

Each defendant is permitted one defense attorney in the courtroom, due to coronavirus rules limiting attendance, and all must wear face masks. The state prosecutor has been assigned bodyguards to protect her from threats. Reporters filled overflow rooms to watch Sunday's hearing on screens, but the trial will not be televised to the public as is customary.

The opening session was scheduled for March but the government's coronavirus stay-at-home orders led the judges to postpone it — an extension that gave the leader more time to build a coalition government and secure his new term in office. Now he comes to the trial from a position of power.

Netanyahu had asked the court to exempt him from attending the opening hearing, arguing that he is already aware of the allegations and that his bodyguards wouldexceed coronavirus limits on courtroom attendance. But the court rejected his request, saying there is room for his bodyguards and he needs to be present for the reading of his allegations. As the trial progresses, Netanyahu could be asked to appear in court three or four times a week, while still serving as prime minister.

It could take months to a year to process preliminary arguments before witnesses are called to the stand. The prosecution's star witnesses are three of Netanyahu'sformer close aides who agreed to testify against their ex-boss and escape prosecution.The court is likely to grant Netanyahu an exemption from personally attending every hearing. It could be several years before a verdict is handed down.

If the judges find Netanyahu guilty, he can appeal the verdict at the Supreme Court. If he lost that appeal he would be required to leave office.

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