ROME Silvio Berlusconi, the four-time Italian prime minister and billionaire media mogul who died on Monday at the age of 86, spent much of the past 30 years embroiled in legal battles.

Here is a breakdown of his many legal cases:

LOTS OF CASES, ONE CONVICTION

Berlusconi was at the centre of a series of investigations and trials, almost all of them opened after he entered politics in 1994. In all, he faced 35 criminal court cases, but only clocked up one definitive conviction.

Under Italian law, a defendant, if convicted, has the right to appeal first to the appeals court, and then to the country's top court, the Court of Cassation.

A sentence becomes enforceable, therefore, only once the appeals process has been exhausted. That takes several years and some alleged crimes are wiped due to the statute of limitations, which dictate how long investigations and trials can last.

"RUBY" CASES

Berlusconi was accused of abuse of office and paying for sex in 2010 with a minor, nightclub dancer Karima El Mahroug, better known in Italy by her stage name, Ruby the Heartstealer.

Berlusconi was initially found guilty in 2013 and sentenced to seven years in jail. The verdict was overturned in 2014 by an appeals court which ruled there was no proof he had known that she was 17 at the time of the encounter. Italy's top court confirmed his acquittal in 2015.

Berlusconi was put in the dock again in Rome, Siena and Milan after being accused of bribing witnesses at his so-called Bunga Bunga parties to lie in the original Ruby trial. He has been cleared in each city, most recently in February in Milan.

SINGLE DEFINITIVE CONVICTION

The only Berlusconi trial that ended with a final conviction was one for tax fraud, false accounting and embezzlement tied to his media empire, which was then called Mediaset. In 2013, the top court confirmed Berlusconi's sentence of four years' imprisonment, three of which were covered by a pardon.

Given his age, the former prime minister was able to complete his sentence as community service from 2014 to 2015. He was banned from political office until 2018.

ACQUITTALS

A total of 10 cases ended with an acquittal. Two of them, including the All Iberian party funding trial, were shut down "because the alleged fact no longer represents a crime" after his government changed the law to his benefit.

Seven resulted in acquittals "because the allegations did not prove to be founded", including trials for alleged bribes to the tax police, bribes to judges and tax evasion. He was acquitted in one case because the judge ruled what had happened was not a crime.

STATUTE OF LIMITATIONS AND AMNESTIES

A further 10 trials against Berlusconi concluded with a decision not to pursue the case to a verdict, many because the statute of limitations came into force, bringing a guillotine down on proceedings, including a case where Berlusconi was originally found guilty of bribing a senator in 2006 to bring down the then centre-left government. A number of the cases were curtailed after a Berlusconi-led coalition reduced the statute of limitations for false accounting. He also benefitted from two amnesties.

DROPPED CASES

Another 10 proceedings ended with a preliminary judge deciding to drop the case without going to trial, including one where he was investigated for alleged connections to the mafia.

CASE PENDING

A trial in which Berlusconi is accused of "inducing people to lie" is still pending in the court in the city of Bari.

He is accused of having paid a businessman to lie to magistrates investigating young women allegedly brought to his residence in Rome between 2008 and 2009, when he was prime minister. As in all the other cases, Berlusconi denied any wrongdoing. The case will closed following his death.

(Reporting by Emilio Parodi and Crispian Balmer, editing by Keith Weir, Frank Jack Daniel and Angus MacSwan)