Christiaan was a crew member of the Alexandria, which had set sail for the Japans from England.
Way of the Warrior
Christiaan was on the ship when it was attacked by the wako, Japanese pirates. While Jack is waiting in his father's room as he had been instructed, he heard Christiaan screaming and banging on the door, begging for help. After a sharp thud was heard, Jack opens the door and pulls Christiaan in, and rips bed sheets to stem the bleeding that is coming from a large throwing knife wound in Christiaan's stomach. But Jack then hears his father screaming in pain, so is forced to leave Christiaan behind in the cabin. Christiaan is later confirmed to be deceased, as Jack finds his "lifeless" body, while searching the ship for the Rutter.