Jan had a rough childhood. He was born out of wedlock, sired by a dead-beat father who ultimately walked out on him and his mom before he had a chance to form any memories. Being single with two kids and little choice, Jan's mom turned to prostitution and drug dealing, eventually becoming drug dependent. Many men walked in and out of her life in her search for love, but it was the boyfriend she had while Jan was 4-8 years old that had the biggest impact on his life. Jan witnessed the way that man was towards his mom and other women, and all of the drug dealing and abuse. Still, he was the only father figure Jan had ever known, so he became an unfortunate role model. Jan's older brother Luke saw it all as well, and although some of it did rub off on him, he wasn't as effected because he was older. Jan also had a close relationship with his big brother Luke, and he had difficulty making friends until he got older, when the boys began falling in with the wrong crowd.

As he came of age, Jan himself started smoking, drinking and smoking weed, seeing neither as harmful as the hard drugs that his mother was addicted to. He started dealing while in high school. The group of kids he hung out with were no different, and were little thugs in their own rite. His grades in school weren't the worst and he still managed to graduate high school, but if he cared to apply himself, he might have done well. Instead, his rebellious friends kept him busy, and there were a few occasions where Jan got suspended for fighting.

Jan grew into a selfish person. Aside from the drug and alcohol abuse, he started sleeping around with just about any woman he found remotely attractive. It became his way of experiencing the intimacy that he desperately craved, without any of the commitment that came with a real relationship. Many hearts were broken along the way, but Jan didn't care. He only cared about how he benefited from it. When he was in his twenties, he came across a Millennium recruiter who visited the strip club that he and Luke co-managed. He offered them both immortality in exchange for helping their organization with their little war. Jan didn't care about their mission, but he agreed so that he would become a vampire, with all of the perks that came with it. Luke became more invested, and as Millennium saw the promise the elder Valentine had, they granted him more abilities so that he could fight Alucard. Jan's selfishness lead them to die in the Hellsing manor during their final mission.