Chuckie at some point became a mob enforcer for Sal Valestra and they ruled Gotham with an iron fist before Batman showed up in Gotham. A man named Carl Beaumont came to them for money and they did gave him money. However, Beaumont didn't pay them back. One night, they visited Carl's house and made threats to pay them back. Carl promised Sal that he'll pay them back in 24 hours which Chuckie agrees on. But, Carl used the time to escape to the Mediterranean and managed to pay them back. Arthur Reeves, Carl's assistant was desperate for cash so he gave the mob the location of Beaumont and told them of his embezzled fortune. The mob sent the hitman who would later become the Joker to kill Beaumont.
Years after the event, Chuckie managed to make his own crime empire and make counterfeit money. After three years, he held a meeting in his casino and managed to make counterfeit money that looked identical to real money. Palmer couldn't tell the difference and Chuckie assured it was looks identical. However, Batman arrived beat up Chuckie's men. Chuckie managed to escape Batman and escapes to his car but he is confronted by a mysterious figure known as the Phantasm. Sol fires at the Phantasm but the figure disarmed him. A noise of another car distracted the Phantasm long enough for Chuckie to get into his car and escape the Phantasm. He later tried ran over the Phantasm with his car but was blinded by the Phantasm's smoke. Chuckie veered and crashed into a nearby building where he was killed. People witnessed the accident from another building and also saw Batman nearby which made them think he was responsible.
His last name is Spanish for sun.
Chuckie Sol makes a cameo appearance on a photo in The New Batman Adventures.