Grand Hutt Council
The Grand Hutt Council, also going by names such as the Council of Elders, Hutt Council, Hutt Ruling Council, or the Grand Council of Nal Hutta, was a governing body of the Hutt species, consisting of five members. These individuals were often referred to as the "Five Hutt Families," although the complex internal politics of the Hutts meant that a single clan could hold multiple seats on the council. While sometimes referred to as the Grand Council, that term more accurately described the larger assembly of Hutts; the Ruling Council was responsible for the everyday management of Hutt affairs, and its leader acted as the spokesperson for all Hutts in treaties and interactions with the Galactic Empire.
History

The Hutt race and all of Hutt Space were governed by the Hutt Ruling Council, another name for the Council of Elders. Following the Hutt Cataclysms, when the Hutts moved to Nal Hutta, it was established thanks to the vision of the Hutt Budhila Hestilic Amura. Only members of the Clans of the Ancients were permitted to serve on the Council; these clans could demonstrate a direct line of descent from the Hutts' desecrated, ancient world of Varl.
They governed all clans without favoritism, and Hutts throughout the galaxy followed their rules. While the specifics of how decisions were made were largely unknown, it appeared that the most influential kajidics (Hutt criminal organizations) had the most power, making the head of the most powerful kajidic the unofficial leader of the Hutt species. The Hutt Council Chamber, where the Council convened, changed locations over time; during the Clone Wars, the Council met in a chamber located within Gardulla the Hutt's Palace.
In 700 BBY, the Ruling Council had to contend with a revolt by several of their enslaved species that was sparked by the circulation of the play Evocar throughout Hutt Space. After suppressing the rebellion, the Council decided to punish Kossak the Younger for his involvement in the affair. He was put to death by acid transfusion, and his remains were placed at the Qedriga spaceport as a warning to all Hutts about the repercussions of tampering with their ancestry.
Zorba Desilijic Tiure was found guilty of illegally removing ulikuo gemstones during the Separatist Crisis and given a forty-five-year sentence at the Girigard Subsurface Correctional Facility. The Grand Council of Nal Nutta tried to get Zorba extradited so that a council of his peers could try him in Hutt Space, but local laws prevented this. The Council employed Cad Bane to find Ziro the Hutt by the time of the Clone Wars, because he had access to potentially harmful data on Hutt activities. Jabba Desilijic Tiure, Gorga Desilijic Aarrpo, Arok, Oruba, and Marlo made up the council at the time.
Oruba was murdered in 20 BBY, and the Hutt Cartel and the Hutt Council were compelled to join the Shadow Collective. Later, after an incident on Nothoiin, Gorga was taken into custody.
During the Second Imperial Civil War, Vedo Anjiliac Atirue and Queen Jool were members of the Council. They were furious about the devastation of Da Soocha, a planet considered sacred by the Hutts, and the bombardment of Da Soocha's moon Napdu, which resulted in the death of Azzim Anjiliac Atirue. They later informed the Galactic Empire that the Galactic Alliance Remnant had sought refuge on Utapau, with Admiral Gar Stazi among them. The goal was to trick the Imperials into believing they had subjugated the Hutts, but it was actually a ruse for Cade Skywalker to kill Sith scientist Vul Isen, who was the one who created the toxin that wiped out all life on Da Soocha and previously Dac. It became known that Hutts had bounties out for Sith and though they did not directly participate in the war, they funded it by bounty hunters and funding the Galactic Alliance Remnant who fought against the One Sith.
Behind the scenes

The concept drawings for the council chamber depict each council member seated at the council's desk, with a banner bearing the symbol of their kajidics hanging in front of them. However, in the show, the banners are positioned between the council members and do not correspond to any specific Hutt.
The fact that Gorga, Oruba, and Arok occupy different seats at the council's desk suggests that there are no designated seats for the council members, with the possible exception of Jabba, whose hologram appeared at the head of the council when the Shadow Collective appeared before the council.
Despite the fact that the council chamber is located in her palace, Gardulla does not seem to be a council member.
The subtitles for the Evil Plans episode on DVD indicate that the council is speaking in ancient Huttese, and Cad Bane admitted that his knowledge of ancient Huttese was limited.