(CNN) -- The trial of Italian Prime Minister Silvio Berlusconi on charges of sex with an underage nightclub dancer and abuse of power opened Wednesday in Milan.
It lasted 10 minutes and was adjourned until May 31.
The case is the latest in a long-running series of legal wrangles featuring the scandal-plagued politician and promises to be one of the most controversial trials ever to take place in Italy.
What is Berlusconi accused of?
Prosecutors allege that Berlusconi paid for sex with Karima El Mahrough, a nightclub dancer nicknamed Ruby who at the time was 17-years-old.
Prosecutors also say, in legal papers seen by CNN, that Berlusconi had sex 13 times with El Mahrough.
They claim he abused his position when he intervened in May 2010 to get her released from the jail where she was being held on charges of theft.
Berlusconi says the allegations are politically motivated and are an attempt to smear him.
In Italy, the age of consent is 14, and it is not illegal to pay for sex. However, paying for sex with a minor (under 18) is a crime, and can be punished by up to three years in jail.
Berlusconi has said the dancer had been introduced as a 24-year-old.
Did he give her any money?
El Mahrough said she did not know Berlusconi well but that she did receive 7,000 euros (about $9,300) from him the first time they met, on Valentine's Day 2010, because a friend told Berlusconi she needed help.
Has he been in court before?
Yes. Many times but on March 28 he made his first personal appearance in court in for eight years. It was a two-hour closed-door hearing in Milan on corruption charges. He and others - including his son - are accused of tax fraud and misappropriation of funds.
What other legal issues is Berlusconi facing?
The 74-year-old Italian PM, currently serving his third term in office, also faces charges of bribing British lawyer David Mills to secure favorable testimony in legal cases.
His trial, suspended last spring after he was granted temporary immunity, resumed this month. Mills denied receiving bribes and his conviction in the case was overturned last year.
He has survived a series of political, corruption and sex scandals over the years, involving allegations of embezzlement, tax fraud and bribery.
Berlusconi has been tried on at least 17 charges since he was first elected prime minister in 1994, but none of the cases have resulted in lasting convictions; several were overturned on appeal.
He has always denied any wrongdoing, and had previously claimed immunity from prosecution, though a 2008 law granting him this was overturned the following year.
How has he reacted to the claims?
Berlusconi insists he has never paid for sex -- "not even once in my life" -- and says any suggestion he did so is "degrading for my dignity."
Both he and El Mahrough, who is now 18, deny ever having had sex with one another.
But the young woman's former roommate told investigators that El Mahrough confided to her that she did have a sexual relationship with the premier.
Berlusconi says he did call the police on El Mahrough's behalf, but denies this was an abuse of power.
He says he thought El Mahrough was related to the since-deposed Egyptian President Hosni Mubarak and he was acting in Italy's interest by trying to avoid a diplomatic incident.
The billionaire media magnate and football club owner says the allegations against him are simply political mudslinging.
His lawyers have called the investigation "absurd and groundless" and a "grave interference" in Berlusconi's private life.
Will this case damage him financially?
A media entrepreneur, Berlusconi and his family were number 74 on the Forbes list of The World's Billionaires for 2010 and worth an estimated $9 billion, so the trials are unlikely to make a significant dent to his wealth.
So, will Berlusconi attend any or all of the trials?
Yes, according to his attorney Niccolo Ghedini, who said: "Absolutely yes, we have decided to blank his agenda for one day per week, every Monday, in order to allow him to participate to all the hearings."
Berlusconi's lawyers have previously argued that courts in Milan do not have jurisdiction in the case -- because of where the alleged crimes were committed -- or the authority to try a prime minister.
What about Berlusconi's political reputation?
Long-running scandals, a playboy lifestyle and a series of well-publicized gaffes have opened the Italian PM up to widespread ridicule.
Berlusconi has survived two votes of no confidence in recent months, and while his personal approval ratings have been dented, his party, the People of Freedom, still enjoys widespread support in Italy.
Has the Vatican commented?
The Vatican has made no comment on 'Rubygate', which is in keeping with normal diplomatic relations between the Vatican City and the Italian state, says CNN's Diana Magnay.
What has the public reaction been in Italy?
In mid-February thousands of Italians took to the streets in some 200 cities across the country in protest of Silvio Berlusconi's alleged behavior toward women.
The largest gathering was in Rome, where organizers said 100,000 people gathered, under the slogan, "If not now, when?"
In Milan, Berlusconi's birthplace, organizers estimated that 60,000 people gathered. Protests also took place outside Italy, including marches in Tokyo and Geneva.
Many Italians on the street were clear about their opinion.
"It doesn't really matter if he is found guilty or not. I find it deeply upsetting when I watch the TV news, when I read the paper and when I hear about Berlusconi and Ruby, I feel sick," said Rome resident Belinzone Gianlice.
"I think that the example that is coming from the higher powers must be different," said Giovanni Nani.
And in Milan, one banner captured the sentiment felt by many Italian women and particularly feminists, "Stop the merchandising of women."
CNN's Hada Messia, Diana Magnay and Dan Rivers contributed to this report.