The French Assassins were the Brotherhood of Assassins located in France. They were most notable for unsuccessfully attempting to finish off the Templars once and for all, and later worked to prevent the Templars from infiltrating the Royal Court.
Early in the 14th century, the Assassins manipulated the French King, Philip le Bel, to attempt and destroy the Templars. They turned the Church against them, the Templars' former ally, and nearly destroyed the Order. The Grand Master of the Templars, Jacques de Molay, and sixty others were burned at the stake, seemingly destroying the Order. However, unbeknownst to the Assassins, nine Templar leaders had gone underground and continued their work secretly.
Not much is known about the French Assassins' activities after this point, until, in the early 16th century, King Louis XII left Paris and quarreled with Ferdinand II over the ownership of Naples, leaving his foreign ministers in charge. These men were Borgia-bought, and targeted the religious reformist Desiderius Erasmus.
To escape the plague, Erasmus planned to hire a carriage out of town, though the Templars disguised themselves as travelers and offered him a ride. With Erasmus' life in danger, the French Assassins and a team of Ezio Auditore da Firenze's Italian apprentices tracked them down, and with coordinated shots, they killed all of the guards. After rescuing Erasmus, he told them that the Templars were holding another Assassin captive.
Following this, the Assassins tried to find their fellow brother-in-arms, who had been captured by Templar men working for the Borgia. A group of Italian Assassins sent from Rome by Ezio were able to receive information from corrupted ministers about the Assassin's whereabouts, and they tracked down Archbishop Georges d'Amboise, before interrogating him. He revealed the names of Templar associated ministers, whom the Assassins later killed and buried.
After that, the Italian Assassins rescued the French Assassin from the manor he was held in, but he eventually succumbed to his wounds. However, the Assassin had been brave enough to reveal only fake information under torture. He also warned his rescuers to be wary of the Orsini, who had ties with the Templars.
In 1511, King Louis XII became tired of Marseille's threats of secession, motivated by the French Assassins, and ordered his army to banish all Assassins from the city. Aided by Ottoman Assassins sent from Constantinople by Ezio Auditore, the combined Assassin force hindered the army's efforts, though without violence.