8 May 2013 Last updated at 17:14 ET

Q&A: Silvio Berlusconi on trial

Silvio Berlusconi says the allegations are politically motivated

Judges in Italy have ruled that the country's former Prime Minister, Silvio Berlusconi, should serve four years in jail after he lost an appeal.

It is the latest in a string of court cases and investigations that have seen the media tycoon accused of, among other things, having sex with an underage prostitute, tax fraud, bribing lawyers and breaching confidentiality.

The legal processes have quickened since Mr Berlusconi left office and lost his immunity from prosecution.

What is the latest case about?

The Mediaset case, brought in Milan, was put on hold in 2010 because of a government immunity law, but restarted on 28 February 2011. Mr Berlusconi did not appear on that day, but appeared on 11 April.

He and other executives were accused of buying rights to US films at inflated prices via two offshore companies. Prosecutors alleged that part of the sums declared was skimmed off to create illegal slush funds, reducing Mediaset's tax liabilities.

He was convicted of tax fraud and sentenced in October 2012 to four years in jail, which was later reduced to one year.

Mr Berlusconi lost his appeal against the conviction on 8 May 2013, with the court reinstating the earlier, longer prison term. He is expected appeal against that ruling at Italy's highest court, the Court of Cassation.

What were the other cases concerning his business practices?

A second case, Mediatrade, also concerned alleged fraud over inflated prices for TV rights. One of the defendants was Mr Berlusconi's son, Pier Silvio Berlusconi, Mediaset's deputy chairman.

The case was dropped in June 2012 in Rome, a decision that was upheld by Italy's highest appeals court in March 2013.

A third case was dismissed on 25 February 2012. It concerned British tax lawyer David Mills. Mr Berlusconi was alleged to have paid him $600,000 (£385,600) to lie under oath in two corruption trials in the 1990s.

Judges threw out the case against Mr Berlusconi under the statute of limitations. Mills himself was convicted of perjury in 2009, but that case also expired under a statute of limitations and he was never jailed.

All the defendants rejected the accusations.

Has he also faced trial over the leaking of a police wiretap?

Yes. Mr Berlusconi was accused of arranging for a police wiretap concerning a political rival to be leaked and published in a newspaper.

Prosecutors brought the case after a transcript of a phone conversation intercepted by the authorities was published in the newspaper Il Giornale, owned by Mr Berlusconi's brother Paolo.

The conversation took place between the head of insurer Unipol and Piero Fassino, who was the leader of the biggest centre-left party and Mr Berlusconi's biggest political rival at the time.

Unipol was trying to take over BNL bank in 2005. Magistrates had ordered the wiretap as part of an investigation into inappropriate interference in the takeover.

Mr Berlusconi was convicted of breaching confidentiality and sentenced to one year in jail in March. However, under Italian law people over 75 can have their jail sentences commuted to house arrest. He is expected to appeal and remains free in the meantime.

Paolo Berlusconi, 64, was convicted of the same charge and jailed for two years and three months.

Is there also a sex case?

Yes. The allegations have been labelled the Ruby case after the woman at the centre of the allegations.

The case was opened on 6 April 2011. Mr Berlusconi is accused of paying an underage prostitute for sex, which carries a three-year jail term, and abuse of power, for which he could face six to 12 years in prison.

Prosecutors allege that a Moroccan dancer, Karima El-Mahroug, nicknamed Ruby, attended several parties at Mr Berlusconi's residence in 2010 and was paid for sex while she was 17 years old, an offence in Italian law.

Both she and the former prime minister deny having sex. She says she did receive 7,000 euros (£5,900) but it was as a gift after a party.

On 19 October 2012 Mr Berlusconi denied in court having any "intimate ties" with Ruby and denied scenes "of a sexual nature" at his parties.

Mr Berlusconi is also charged with abusing his power of office by trying to persuade police to release Ms Mahroug from custody after she was arrested in Milan on suspicion of stealing money and jewellery in a separate case.

He has acknowledged the phone call but says it was made as a favour to former Egyptian President Hosni Mubarak, whose granddaughter he believed Ms Mahroug to be.

A verdict is expected in coming weeks.

Why did the trials all come up at once?

In January 2011, Italy's Constitutional Court swept away part of a law passed in 2010 granting 18 months of immunity to Mr Berlusconi and some of his senior ministers.

The ruling meant that it would be up to individual trial judges to decide whether he should be allowed to claim that his job was a "legitimate impediment" to a court case.

A legitimate impediment could include a state visit, an EU summit or perhaps a cabinet meeting while he was still prime minister.

How can he afford to fight so many cases?

Mr Berlusconi is not short of money: Forbes magazine reckons his fortune to be about $9bn. However, he estimated back in 2009 that he had spent more than $200m in legal fees over two decades, with more than 2,500 court appearances in 106 trials.

What does Mr Berlusconi say?

He says he is being targeted by left-wing Milan prosecutors pursuing a vendetta against him. He has complained of being "the most persecuted man in the entire history of the world".

After the original Mediaset sentence, he condemned the decision as a "political verdict" and complained of "judicial harassment".

How often has Mr Berlusconi appeared in court?

Rarely. He has sought to stay out of court, querying the legitimacy of the court proceedings or the motives of the judiciary, and passing immunity laws.

But since his protection from prosecution was revoked, he seems to have adopted a new tactic. He said he would set Mondays aside for court appearances.

His attendance at a preliminary hearing of the Mediatrade trial on 28 March 2011 was his first court appearance in eight years.

He has appeared on several occasions since, including at the Ruby trial. At his appearances, he has launched stinging attacks on the cases and the judiciary.