Mentor

"The Mentor's role is to oversee and coordinate the actions of the Order in the pursuit of harmony through free will."

- The Mentor, 2000.

The title of Mentor was an honorific name, given only to leaders of the Assassin Order who had obtained an extraordinary amount of skill and wisdom, and subsequently used these skills to tutor aspiring apprentices.

These Assassin leaders were assigned to direct the branches of Assassins spread around the globe, who were awarded with the unofficial title of Mentor once they had trained a specific number of apprentices and received a high amount of skill and wisdom.

During 2000, the title of Mentor had become official and singular, with only one single Mentor leading the entire Assassin Order. Typically, the Mentor acted as a living conduit for all of their predecessors, possessing the sum total of all of their knowledge and experience, which was passed down from Mentor to Mentor. However, following this Mentor's death, the Great Purge was enacted, with the leadership of the Assassin Order under a specified Mentor waylaid in efforts to evade detection by the Templars.

Middle Ages
The first known usage of the term "Mentor" was during the Crusades in the Levant, where the leader of the Levantine Assassins, Rashid ad-Din Sinan, was most commonly referred to as "Al Mualim," Arabic for "the Mentor." When Al Mualim used his Apple of Eden to brainwash the Assassins in Masyaf and claim absolute control over them, he was confronted and killed by his student Altaïr Ibn-La'Ahad.

Altaïr succeeded Sinan as Mentor, and made many reforms and innovations to the Assassin Order. These changes along with his efforts to spread the influences of the Assassins made him the most legendary and respected Mentor of the entire Order.

In 1227, Altaïr's childhood rival Abbas Sofian staged a coup d'état against Altaïr, resulting in the Levantine branch falling under Abbas' leadership and of Altaïr's self-imposed exile. Usurping the title of Mentor, Abbas tyrannically ruled the branch and its headquarters of Masyaf with a disregard for the Creed, until he was killed by Altaïr in 1247, marking the return of Altaïr's rule as Mentor. Altaïr held this title for ten more years, until he disbanded the Levantine Assassins from Masyaf and passed away in his library during the Mongol attack on Masyaf on 12 August 1257.

Renaissance
"You will now be known as il Mentore, the guardian of our Order and our secrets."

- Niccolò Machiavelli to Ezio Auditore.

In August 1503, Ezio Auditore da Firenze was promoted to the rank of Mentor of the Italian Assassins by the de facto leader Niccolò Machiavelli, for his years of exploits against the Borgia family. He held this position for several years, and also acted as a leader and teacher to the Ottoman Assassins during his time in Constantinople.

Ezio resigned as Mentor upon returning to Italy from the Ottoman Empire in 1513, and assigned Lodovico Ariosto to become his successor. As of 1511, a descendant of Altaïr Ibn-La'Ahad, Iskender, held the position of Mentor of the Egyptian Assassins. Around this time, Iskender received aid from Ezio Auditore da Firenze after having been arrested and imprisoned.

Some time after Ezio's retirement from the Assassin Order, the Chinese Assassin Shao Jun and her Mentor attempted to flee from China, to escape from Emperor Jiajing's purge of the country – which included Assassins – and request Ezio's aid. However, once the two of them had arrived in Venice, Jiajing's Imperial soldiers caught up with the Assassins, and Jun's Mentor died while trying to secure her safety and escape.

Colonial America
During the later 18th century, most of the Assassins in Colonial America had been wiped out, leaving the survivor Achilles Davenport as the Mentor of the Colonial Brotherhood. During the time before the American Revolutionary War, he was hesitant with training new assassins, due to his agreement with the Templars concerning his life. Eventually though, he trained the native Ratonhnhaké:ton as a member of the order, leading him until his death.

Under Achilles' reign, the Brotherhood regrew in the area, and the fight led by Ratonhnhaké:ton greatly diminished the influence of the Templar Order in the colonies. He led from his home in the manor atop the Davenport Homestead, which overlooked the naval power that Achilles had created for the Brotherhood. Following his death, Ratonhnhaké:ton assassinated the remaining Templar conspirators, presumably becoming the de facto Mentor.

Modern times
During the mid-19th century, the Mentor of the Indian Brotherhood of Assassins was Hamid. Under the leadership of Hamid, the Assassins were a strong presence in the Sikh Empire. Hamid instructed Assassin Arbaaz Mir to find a Piece of Eden known as the Koh-i-Noor. Located in the palace of Maharaja Ranjit Singh, the Piece of Eden was said to hold an immense amount of power and was sought heavily by the Assassins as well as the Templars.

By the late 19th century, one Mentor heavily involved himself with the Russian Assassins' efforts to depose the aristocratic rule of the Russian Royal House. In 1888, he assigned Nikolai Orelov to assassinate Tsar Alexander III while the latter was traveling from the to Saint Petersburg. Later in 1908, the Mentor once again hand-picked Nikolai Orelov to retrieve the Imperial Sceptre, one of the Staves of Eden, from a Templar research facility in Tunguska.

During the 20th century, the entire Assassin Order was united under a single Mentor. By 1998, an individual known only as "the Mentor" led the Order, though his name and location were always kept secret – even from the Assassins themselves – for safety concerns, and he always stayed mobile to avoid being located. In November 2000, the Mentor invited Daniel Cross into his secret Dubai headquarters after having monitored his actions for two years, believing him to be a worthy apprentice.

However, Daniel, whose brain had been unknowingly experimented upon by Abstergo Industries and imprinted with an impulse to kill the Mentor, subsequently assassinated him after having been rewarded with a Hidden Blade. Following this, the Assassins were thrown into disarray and forced underground, and the mantle of leader was eventually picked up by William Miles.