During the Napoleonic Wars, Jan changed sides and left the Belgian army only to discover that his wife and children were killed during the bombardment of his city by the French troops. He soon became an agent of Emperor Napoleon I.
Agent of Bonaparte
In 1805, Jan was sent to Libya on a mission, officially to acquire textiles. While they were both sailing toward Libya, Jan met Solomon "Solo" Bolden, the Black Cross of the Templar Order who was at the time posing as a slaver. Despite finding him annoying, Bolden nevertheless accepted to protect Jan during his mission for Napoleon after the Flemish helped him fend off pirates sent by Sultan Selim III to kill him. To secure Bolden's help, Jan also promised to help the Templar enter the palace, the Sultan being behind the attempt on his life.
Once in the port city of Derna, the two men took camels and traveled to Tripoli, where they eventually met with Jan's contacts in a local tavern. There, Edmund, a deserter of the marines and Ahkbar, a shady local, revealed to them the existence of a secret underground tunnel used by the Sultans to discreetly smuggle precious cargo into the palace. Following the departure of their companions, Bolden and Graff bonded over several drinks with the Black Cross trying to learn what "the diamond" mentioned by Edmund was, until being interrupted by the latter being shot by guards in the street.
Later, they entered the tunnel after Graff picked the gate's lock, but were confronted by several men waiting for them. During the brawl, Ahkbar, who was in fact an agent of the Sultan, stabbed Bolden in the back. Subsequently, Jan was thrown into the palace's dungeon where he met another prisoner who was revealed to be Bolden's predecessor, Tavis Olier.
Becoming a Templar
During the three years they were imprisoned together, the old Black Cross trained Graff and inducted him into the Templar Order until one day. on 29 July 1808, Olier heard that the Assassins were coming to buy the artifact in possession of the Sultan. In order to escape, the two Templars assaulted the guards, bringing them food but, Olier had to sacrifice himself to allow Graff to accomplish their mission.
After dispatching several guards, the Templar finally reached Selim's apartment where he discovered that Ahkbar, who was an Assassin, had already poisoned the monarch and had taken possession of his prize, the fabled Koh-i-Noor. After revealing that he intended to betray the Brotherhood and keep the artifact for himself, Ahkbar tried to use the Koh-i-Noor and its power to create illusions, but Graff saw through it and killed him.
A group of Assassins quickly surrounded Graff, but having heard Ahkbar's speech and after the Flemish told them that he wanted no part in their secret war against the Templars, they spared him and left with the box containing the artifact. However, Graff had lied about his commitment to the Order and had in fact removed the diamond from its box before giving it to the Assassins.
Later life and legacy
Shortly afterwards, Jan left the Barbary Coast and sought out Bolden's widow, informing her of Solo's exploits. The pair grew close, and after a night of passion, Graff fathered a child with her, who carried on the Bolden name. Their unanticipated coupling threatened to derail Juhani Otso Berg's pursuit of the Koh-i-nor in the 21st century when he was researching the Bolden bloodline with Graff's great-great-grandson André Bolden, but the two managed to pick up the trail.
Equipment and skills
Van der Graff was a trained soldier and a skilled swordsman, besting pirates as well as palace guards, and he was also a skilled in lockpicking. After being trained by Tavis Oliver for over three years, he became far more skilled, trained in stealth and unarmed combat. He was capable of throwing a sword directly into an enemy's chest. Van der Graff also seemed to have enhanced his senses enough to best the illusions created by Ahkbar and sense the arrival of the Assassins. He was also skilled in deception, having managed to convince a team of Assassins that he had no loyalty to the Templars. He was also fluent in Arabic.