Bill Sikes is in his thirties. We don't know much about his childhood or background. We can most likely assume that he grew up poor somewhere in the ghettos of London. We do know that he is very strong and stout and that he often works with Fagin on various criminal endeavors. He has a reputation around town as being a very violent man.
Bill and his Dog
Bill Sikes has a bull terrier named Bull's Eye that he beats. He is also romantically involved with Nancy, who has been a thief since the age of six. Nancy is also a prostitute. Bill is certainly courageous and willing to risk his life in the name of crime. He does even show compassion for Oliver and Nancy at various points in the novel. However, we shouldn't throw too many compliments his way. His violent and quick temper should take center stage.