- "Good shot, Dorothée!"
- ―Didier to his sister, 1789
Born as the older brother of Dorothée Droit, Didier was destined to inherit their family's fortune. His father was a count in northern France, but when this one died during the Seven Years' War, Didier felt he was not ready to become the next in line. So, days before the coronation that would make him the new count, Didier fled. However, the night he was going to flee, his sister said she did not wanted to be married away to someone else to make the Droit-name survive – she came with him. The role was therefore given to their younger brother, Dapoix.
Arriving in the city of Calais, the siblings found themselves on fresh ground. They would create a new life here, trying to run a grocery. The food was good, but a burglary turned their lives up-down. Already deep in debt because of their wish to build the grocery and obtain the goods, the siblings had to sell everything they had to pay back – but the housekeeper still needed the rest of the rent. While the sister sold herself on the streets, Didier chose to do pity thefts. When he was captured once, he was being released for a loan. The siblings now needed to pay that back too.
When they heard of a politician named Bourienne helped those in need, the Droit-siblings immediatley sought his advices. The man answered that he would help them if they chose to join his forces of mercenaries – in return, he would pay their debt. When Didier asked what would happen if they tried to run off, the politician answered that they would much like not to find it out.
As a mercenary, Didier's task was to make sure his employer did not run into ghosts of the past or future threats. His base of operations was soon in Calais and sometimes in the city of Rennes. In 1782, Didier and other mercenaries working for Bourienne was sent to Rennes: Bourienne was to carry out some transactions for the Templar Order, but some Assassins seemed to wait for him. Didier and several of the mercenaries would get paid a lot of money in order to remove the threats. Killing one of the Assassin-lieutenants, Didier would be stationed in Calais with much money to go with. In the city, he would work alongside the mercenaries Babineaux and Bélanger, where he and his sister would be the leader of the mercenaries.
During Didier's time in Calais, he and his associates became known with the leaders of The Turk, an organization established by the Templars: Shamar al-Djin and his Board. Through one of the lieutenants of al-Djin, Didier and the mercenaries were allowed to stay at a pub. From there, the mercenaries would eliminate enemies of The Turk, carrying out work for them also. As a mercenary, Didier's loyalty lay were the money was. This lead to his downfall. Loyal to both The Turk and Bourienne, Didier and his associates stayed at the pub where lieutenant Murat ruled – even after her death. A few days later, an Assassin entered the locals. Didier and the other leaders of the mercenaries took an interest in him, and later they followed him out of the building. After threatening the Assassin, the man turned around quickly – shooting monsieur Babineaux in the head. After killing him, the Assassin soon wounded Didier – making him loose it – then moving over to Bélanger. The Assassin disarmed Bélanger before he stabbed him with his sword and hidden blade. Watching the death of the merceanry, Didier rose from the ground and ran towards the Assassin. Strong as a gorilla, Didier lifted the attacker from the ground and threw him four meters over the square. Didier walked up to his victim, picking up the cleaver from his belt – he had put it back when he charged toward the Assassin. As the Assassin rose from the ground, Didier threw the cleaver. The man lay himself to the ground just in time. Quickly back on his feet, the Assassin was to eject the hidden blade when he was shot in the arm by a pistol Dorothée wielded. Didier laughed, stating: "Nice shot, Dorothée!" Didier grabbed the Assassin's arm with the hidden blade, bending it backwards – he also held the free hand of the Assassin, making it impossible for the man to do something with his hands. However, a kick below the belt forced Didier to the ground. The Assassin was quick, placing the blade in the throat of Didier. Just moments later, Dorothée Droit's corpse lay beside her brother's.
- Didier is the French form of Desiderio – meaning "longing, desire".
- Droit is French for the number three