Throughout the history of the Assassin Brotherhood, several branches adopted an Assassin Council, or Council of the Brotherhood, as their governing body. The practice began sometime in the first millennium under the Levantine branch of Hidden Ones, who outlined in their founding statutes a provision for the creation of a Council and its dissolution as required by a chapter's Mentor, and was carried over in 1090 when their leader Hassan-i Sabbāh formally reorganized the Hidden Ones into the Levantine Brotherhood
During the Renaissance, the Mentor of the Italian Brotherhood led an Assassin Council comprised of several local Master Assassins. The French Brotherhood during the French Revolution and the British Brotherhood during the Industrial Revolution were also led by their own respective Assassins Councils.
- Swami: "A meeting of the council has been called for tomorrow morning."
- Altaïr: "The what?"
- Swami: "With Malik imprisoned, a council was formed to oversee the Order, in accordance with the statutes of the Brotherhood."
- —Altaïr being told by Swami about the newly-formed council, 1227.[src]
During their early years in the Levant, the sect of Hidden Ones operating in the region set rules establishing the conditions for a Council. Its duties included judging the readiness of their members for missions, meeting to discuss the group's actions against the Order of the Ancients moving forward, and overseeing the Brotherhood in the event that a suitable Mentor could not be appointed.
In 873, the Levantine Mentor Rayhan wrote a letter to Hytham, an acolyte studying under Basim Ibn Ishaq, informing him that the council was pleased at Basim's apparent initiative to hunt their enemy in England and at his decision to bring Hytham to accompany him. Seeing that Hytham had potential, Rayhan advised him to follow his teacher's lead if he sought to "ascend to greatness".
However, Basim later attempted to kill his new allies Eivor Varinsdottir and Styrbjorn Sigvaldisson of the Raven Clan while in Hordafylke, only to be defeated and trapped in the Yggdrasil supercomputer. On returning to the Norse settlement of Ravensthorpe in Ledecestrescire, Eivor told Hytham of the sudden turn of events, and he informed Rayhan and the Council of the news in his subsequent report.
In 879 CE, the Mentor Fuladh from the Justanid region of Persia was set to host a council at the newly-constructed fortress of Aluh-Amut in Deylam. Rayhan invited Hytham to attend the council and give a full account of Basim's betrayal to the rest of the Brotherhood, and to be present when the Council promoted him from the rank of Acolyte.
In 1090, Hassan-i Sabbāh formally reorganized the Hidden Ones into the publicly known Levantine Brotherhood, but still maintained the decrees set by the Hidden Ones centuries before regarding Councils and how the order was to function. The next notable Council would not be seen until nearly 140 years later. Following the departure of Mentor Altaïr Ibn-La'Ahad from Masyaf—the Levantine Assassins' seat of power in the 13th century—to combat the growing threat of the Mongol Empire, and the imprisonment of the interim Mentor Malik Al-Sayf on the false charge of murder, the Assassins convened a council headed by Altaïr's rival, Abbas Sofian.
Sofian's council numbered ten Assassins in total, and upon Altaïr's return to Masyaf in 1228, consisted of men the former Mentor considered to be among the Order's most weak-minded and conniving, including the likes of Farim. Soon after his return, Altaïr met with Sofian and the Assassin Council to discuss his quest to halt the Mongols' advances and his success in assassinating Genghis Khan, the Mongol leader. Though the statutes of the Levantine Brotherhood once would have allowed the returned Altaïr to assume leadership again and dissolve the sitting council, Sofian's scheming had altered the statutes' ordinances so he and his council could stay in power, having declared Altaïr too compromised to lead.
When Altaïr later took back the Levantine Order from Abbas Sofian's leadership in 1247, the Mentor elected not to continue the Assassin Council, though he retained several trusted advisers.
- "Business first. I am calling a meeting of the Council of the Brotherhood here tonight."
- ―Mario Auditore.[src]
During the era of the Renaissance, the Italian Assassins maintained an Assassin Council, otherwise known as the Council of the Brotherhood. Comprised of several notable Master Assassins, often under the oversight of the current Mentor, the Assassin Council was responsible for choosing the Italian Brotherhood's leader and ratifying significant decisions regarding the direction of the Order.
In 1500, several members of the Italian Assassin Council—including the Assassin leader Mario Auditore and Niccolò Machiavelli—met at the Villa Auditore in Monteriggioni to hear Ezio Auditore da Firenze recount his confrontation with Pope Rodrigo Borgia and the discovery of the Vatican Vault beneath the Sistine Chapel. In the aftermath of Cesare Borgia's devastating attack on Monteriggioni that cost the life of Mario Auditore, Ezio and Machiavelli were appointed dual chiefs of the Council by virtue of their deeds furthering the Assassin cause.
The Assassin Council later ratified the ascension of Ezio to the role of Mentor and leader of the Italian Assassins. During Ezio's tenure as Mentor, the Italian Assassin Council could count Machiavelli, Bartolomeo d'Alviano, Rosa, La Volpe, Paola, and Claudia Auditore among their numbers, each offering the Mentor aid, intelligence, and advice. When Ezio later stepped down as Mentor, and named Lodovico Ariosto as his chosen successor, the council was left to ratify his decision.
The French Assassin Council was active since at least the mid-18th century, dispatching John de la Tour to the early American Colonies. Operating under the council's orders, de la Tour aided in establishing a new Colonial Brotherhood around 1746, though his death at the battle of Louisbourg left control of the Colonial Assassins in the hands of Mentor Achilles Davenport.
In 1748, Gaspar Velasquez and his associates in Spain began working on the blueprints for a powerful new brig to bolster the Colonial Assassins. However, they were unable to build the ship themselves due to the threat posed by the British Rite of the Templar Order. The following year, the plans were given to the French Council, who had the ship—dubbed the Aquila—constructed in Brest, France, and delivered into the possession of the Colonial Brotherhood.
By 1789, the French Council was led by the Mentor Mirabeau, and operated out of the Assassin sanctuary beneath the Sainte-Chapelle in Paris. At this point, the council was composed of four other Master Assassins: Pierre Bellec, Sophie Trenet, Hervé Quemar, and Guillaume Beylier. In July of 1789, they inducted Arno Dorian into the Brotherhood, and as the French Revolution broke out, sought to bring about a peaceful resolution to the conflict.
In 1791, Mirabeau was murdered by his fellow council member Pierre Bellec, for attempting to establish peace with Élise de la Serre, a Templar betrayed by her own Order. Bellec, having been witness to Templar atrocities committed in the name of purging the Assassins, viewed Mirabeau's push for peace as treason against the Assassin Order. Bellec's crime was uncovered not long after by Arno, leading the two Assassins to engage in a fight that left Bellec dead and the Assassin Council deprived of two of its members.
Thereafter, chairmanship of the French Council fell to Trenet, who later lead the council to expel Arno from the Assassin Order. They did not approve of his selfish reasons for joining the Brotherhood, nor the manner in which he repeatedly acted outside the tenets of the Creed, brashly killing targets without the council's consent, in order to pursue a personal vendetta against the rogue Templars who killed his adoptive father. The French Council banished Dorian, but did not seek to punish him further, and would ultimately welcome the young Assassin back years later, after he had matured and shown true dedication to the Brotherhood's cause.
- "You know as well as I do that London has been the domain of the Templars for the last hundred years. They are far too strong yet. Patience. [...] The Council shall guide us, sound advice that your father would have seconded. I shall see you back in Crawley."
- ―George Westhouse, on the Council's reluctance to challenge the Templars' control of London, 1868.[src]-[m]
By the year 1868, the British sect of the Assassin Brotherhood was overseen by an Assassin Council that was reluctant to take action against the Templars that so thoroughly controlled London at the time. Against the orders of the council, the young British Assassins Jacob and Evie Frye nevertheless traveled to London to help Henry Green, the leader of the city's remaining Assassins.
- Assassin's Creed: Brotherhood (first appearance)
- Assassin's Creed: Revelations (novel) (mentioned only)
- Assassin's Creed: Unity
- Assassin's Creed: Syndicate (mentioned only)
- Assassin's Creed: Underworld (mentioned only)
- Assassin's Creed: Valhalla (mentioned only)
- Assassin's Creed: Valhalla – To Serve the Light...
- Assassin's Creed: The Secret Crusade – 
- Assassin's Creed: Valhalla – 
- Assassin's Creed: Valhalla –  / Viking Expansion notes: "A Letter from Mentor Rayhan"
- Assassin's Creed: The Essential Guide
- Assassin's Creed: Brotherhood novel – 
- Assassin's Creed: Revelations novel – 
- Assassin's Creed: Brotherhood
- Assassin's Creed: Rogue – War Letters – 
- Assassin's Creed: Unity – Rebirth
- Assassin's Creed: Unity – Graduation
- Assassin's Creed: Unity – Meeting with Mirabeau
- Assassin's Creed: Unity – Confrontation
- Assassin's Creed: Unity – The King's Correspondence
- Assassin's Creed: Unity – Bottom of the Barrel
- Assassin's Creed: Unity – The Temple
- Assassin's Creed: Unity – Dead Kings – A Crown of Thorns
- Assassin's Creed: Syndicate – A Simple Plan