- "I was just an angry peasant, wanting a revolution. I thought that the King was the most evil thing ever. That was until the Assassins showed me the truth. Until I discovered the real evil... The Templars, and their quest to enslave us all. I will hunt them all down, and smite their evil from the earth. For that is my destiny as an Assassin."
- ―Aiden Millard to his son.
Aiden would wear a black hood with a red assassin logo on the dip.
Aiden's brace was covered in intricate engravings showing him fighting against the King's forces.
Aiden's hidden blade was silver, a centimeter and a half longer and engraved into it were the words:
'La justice n'est pas l'égalité' (Justice is not Equality)
- "I've seen comrades executed, friends shot, woman and children massacred and villages burn because of this dreadful war. The King does this to weaken our spirits and make us fearful, but all this makes me braver, stronger and more hateful of His Majesty. Viva la Revolution!"
Aiden fought in the French Revolution, becoming one of their greatest soldiers as a matter of fact. Despite this, Aiden was severely wounded during one battle, and his fellow soldiers rode over him, completely ignoring his body; even after the rebels' victory, they left him to die.
He was eventually saved by a woman cloaked in white and armed with swords and daggers. She took him to the Assassins' hideout in Paris where she nursed him to health and told the leader of the Assassins, Jacques Mulner, of Aiden's amazing skills in combat. She also recommended to Jacques that Aiden join the Assassin Order, to which Jacques reluctantly accepted him as a member.
Aiden, after only a year of training, became a full-fledged Assassin. He proved to be the Order's greatest member, and he killed many targets with ease. He usually did contracts alongside his wife Yvonne Cartiers, who happened to be the woman who saved him. Aiden was said to be nearly as great as Altaïr Ibn-La'Ahad himself, and in 1828, he became the leader of the Assassins, due to Mulner's tragic death.
Aiden's later life was pretty uneventful, with the only key moments being his retirement, following which he, Yvonne and his son Alek moved to a lakeside villa on the Italian island of Sicily.