Roman Sionis was born to wealthy and utterly self-absorbed parents who cared more about their social status than their son; moments after his birth, the doctor carelessly dropped him on his head. Roman's parents were less concerned about their son's well-being and more concerned about covering up the entire incident out of fear of how their wealthy friends would react to the news of their son's injury. A second incident occurred when he was a child: While at the Sionis family country estate he was attacked by a
rabid raccoon. This incident was also covered up by the Sionis family, who forbade Roman to mention it to anyone.
Further adding to the cauldron was his father's "friendship" with
Thomas Wayne; both of Roman's parents disliked the Waynes and were quite vocal about it in private with their son. However, to their son's dismay, they continued to associate with Thomas and
Martha Wayne, to the extent of literally forcing him to become friends with their son, Bruce. His parents' hypocrisy had a deep impact on him, and he grew to hate and resent them and the "masks" they wore in public.
After graduating from high school, Sionis was given a high ranking position inside his father's company, Janus Cosmetics. There, he met and fell in love with Circe, a
working class secretary. His parents did not approve of the relationship and made it clear that they wanted him to break it off. Enraged, Sionis burned down the family's mansion, killing both of his parents. Upon their deaths, he inherited the family fortune and business. Sionis was not the businessman his father was and eventually ruined Janus Cosmetics by funding a failed line of face-paint make-up. In desperation, he threw large sums of money at the staff chemists to create a product to save the company, and what came back to him was a kind of water-proof makeup. The product was rushed to market without proper testing, and once it hit the market turned out to be a deadly
toxin which disfigured several hundred women.
Circe, now Sionis' fiancée, broke up with him in front of his entire staff. At that time, now successful mogul Bruce Wayne offered to bail out the company on the condition that Sionis give up control and allow Wayne to appoint his own Board of Directors. Sionis agreed, but was furious at the humiliation he had suffered. He went to the family
mausoleum and broke his father's
ebony coffin lid. From a piece of this, Sionis carved a mask, becoming
"Black Mask".
Despite having proved inept at business, Sionis finds he has an amazing aptitude for crime, and he soon has a large gang working for him. Calling them the False Face Society, the one requirement is that all members must select a mask from his collection and wear it at all times when on the job and in his presence. They become more and more powerful in the Gotham underworld, until Black Mask decides it is time to take his revenge on Bruce Wayne. He begins
kidnapping Wayne Enterprises executives, putting masks on their faces coated in the deadly make-up once made by Janus Cosmetics. He also targets Circe and forcibly disfigures her with the chemicals in order to force her to reunite with him. Circe ultimately commits
suicide, leading Black Mask to replace her with a mannequin that he talks to as if it were a real person.
These kidnappings attract Batman's attention, and he begins hunting down the False Facers. He slowly begins to dismantle the organization until he finally finds Black Mask in the ruins of the Sionis Family home. Black Mask lights the wreckage on fire, in an attempt to "kill" his old self and become his new self, Black Mask. Batman saves him, but the mask had been burned onto Sionis' face and leaves him disfigured.
http://en.wikipedia.org/wiki/Black_Mask_(comics)#cite_note-dc-ency-0