Leone-Forelli-Sindacco gang war

Trouble between the Leone Family, Forelli Family and Sindacco Family started at least in the mid-1980s and lasted until 2001, the last years events shown in the 3D Universe. The Vercetti Family and the Sicilian Mafia, two other mafia families, have also been involved in the mafia wars. The Vercetti Family working against the Forelli Family and the Sicilian Mafia working against the three families.

1971
In 1971 Tommy Vercetti, the protagonist of Grand Theft Auto: Vice City, killed eleven men in the Harwood district of Portland in Liberty City. It is unknown whether the men were members of the Leone or Sindacco families, however, this is likely as the city is shown to be mafia controlled in Grand Theft Auto: Liberty City Stories.

1986
In 1986 Tommy Vercetti was released from prison, with Sonny Forelli assisting his release, and was sent to Vice City by Sonny. This was partly to establish the Forelli Family in the city and partly to get Tommy out of Liberty City, where he would be easily recognised. Vercetti and his companions, Harry and Lee, are met by Forelli-contact and Ambulance chaser Ken Rosenberg and immediately drive to a drugs deal. The deal, involving Victor and Lance Vance, is ambushed by Ricardo Diaz's men. This leads to angry Sonny threatening Tommy to get his money back.

Throughout the events GTA Vice City, Tommy Vercetti begins to build up his own business empire within the city     but does not pay Sonny Forelli his money back. Sonny then begins to send his men to collect money from Vercetti's businesses. Vercetti kills the men. Sonny Forelli then arrives in the city and confronts Tommy at his mansion on Starfish Island. Sonny reveals that he set Tommy up in 1971 and that Lance Vance, who had been assisting Tommy, had joined him. A shoot-out then begins, with Tommy managing to kill both Sonny and Lance. This defeat to Vercetti saw the Forellis' attempts to move into Vice City end.

Mid 1980s
In the mid-1980s Salvatore Leone became the Don of the Leone Family in Palermo, Sicily after a bloody power struggle, which also involved the death of his brother. Salvatore then moved from the "old country" to a mansion in Saint Mark's, Liberty City.

1986-1992
After the death of Sonny Forelli the Forelli Family begin to lose power, bringing the three families onto a more equal playing field. There continues to be trouble between the three Liberty City families, with Salvatore's cousin being killed by the Sindacco Family. The Sindacco Family, however, are losing money with a casino in Las Venturas, Caligula's Casino. Sindacco Family representative Johnny Sindacco goes to Salvatore's mansion in Saint Mark's to gain an investment from the Leone Family. Salvatore agrees to invest money into the casino, along with the Forelli Family, leading to the three families each owning a third of the casino. However, the Sindacco Family are forced to removed Mickey, their man running the casino, and replace him with someone the three families can control but who will remain neutral.

In Vice City, the Vercetti Gang remain a strong force, although Ken Rosenberg's continued drug use leads to him being disbarred from being a lawyer and entering rehab in Fort Carson. After leaving rehab he phones Tommy Vercetti, but can not get through, leading to him losing contact with Vercetti. The three Liberty City based families are aware of Rosenberg's stint in rehab and see him as an easy man to control and so convince him to run Caligula's Palace.

1992
By the events of Grand Theft Auto: San Andreas, Rosenberg has quickly relapsed and once again using drugs, scared that he will be killed if one of the families attack another. This, along with Salvatore's insistence that he wants his money back quickly, put Ken into a difficult position. He has only one friend, a parrott called Tony. However, Kent Paul, a friend from Vice City, finds Rosenberg along with his new musician Maccer and ally Carl Johnson. Carl begins to help Rosenberg and Salvatore Leone, however, he does have plans to rob the casino alongside the Triads. Carl at first maintains the peace between the three Liberty City based families by rescuing Johnny Sindacco from the Forelli Family. The three families, however, quickly begin to fight each other. Johnny Sindacco dies of a heart attack after seeing Carl, who was responsible for putting him in the hospital. Carl Johnson kills Forelii Family hitmen in a plane who were sent to kill Salvatore Leone, as an attempt to take over the casino. Carl also flies back to Liberty City where he kills a high ranking Forelli Family gang member at Marco's Bistro. Carl has now gained Salvatore's trust, in part as he had worked with his son Joey Leone and in part because of the jobs Carl has done. However, Carl and the San Fierro Triads pull off a heist at the casino, leading to a big money loss for all three families.

1992-1998
Sometime in 1994 Don Leone sent out Toni Cipriani to kill an unnamed made man from either the Sindaccos or Forellis. Toni murders the man and "lays low" for 4 years until 1998.

1998
On October 30, 1998, Toni Cipriani came back to Liberty City to find out that Vincenzo Cilli had taken over his position in the family. Now back at the bottom of the ladder, Toni finds himself working for Vincenzo, doing many favours for him such as picking up a drug dealer working for him and dropping him off at Chinatown to deal drugs there, killing members of the Sindacco family who were dealing on Leone turf, and picking up members of Vincenzo's crew after they botched a gas station stickup and evading the police. After Toni was ambushed by the police for picking up a car with cocaine stored in the trunk as a favour for Vincenzo, Toni severed his ties with him and instead started working for JD O'Toole, a Sindacco barman who had turned against Paulie Sindacco in his bid to become a member of the Leone family, performing jobs for him such as rescuing Salvatore from Paulie's Revue Bar before the LCPD arrested him. After proving himself in the war against the Sindaccos, Toni was contacted by Salvatore, who had more work for him, and at the same time Toni's mother demanded that Toni visit her. Toni started working for both of them, performing jobs for Salvatore such as delivering a bribe to a union boss at the docks and plying the dockworkers with prostitutes to gain their support, and performing jobs for his mother such as murdering several Triads to prove his bravery and murdering Giovanni Casa for not paying his mother protection money. Later on, Toni was ambushed by hitmen outside Momma's Restaurante who had been hired by his mother to kill him, but Toni survived the ambush (Ma Cipriani's hitmen continue to ambush Toni from that point on until he became a made man). Toni later started working for Salvatore's wife Maria Latore, getting him in trouble as she shoplifted, almost got kidnapped by the Sindaccos, putting herself up as 1st place prize gift in a street race, getting beaten up by the Liberty City Bikers leader (who Toni killed), and almost overdosing. Toni starts working for JD again where he saves Salvatore's life and the Leone get into a gang war with the Sindaccos, but that's not all, The Sicilian Mafia were paying the local gangs to start a mob war between the Leones, Sindaccos, and Forelli Families, led by Salvatore's Uncle Uncle Leone. This leads to a lot of attacks forcing the 3 families to leave Portland Island into Staunton Island.