You might not know its name, but if you’ve ever enjoyed a Marvel or DC comic – or watched one of the many movies or TV shows based on them – chances are you’ll have enjoyed or benefited from the work of artist Neal Adams. His distinctive style – dramatic, brooding, and daring – helped revolutionize the way comic books looked in the late 1960s and early 1970s, and he had revered series on titles like Batman and x-men who are still revered to this day.

Sadly, Adams passed away Thursday in New York. He was 80 years old. According to The Hollywood Reporterthe cause of death was complications from sepsis.

Adams’ accomplishments include playing a significant role in reshaping the way Batman was watched following the campy 1960s TV show. Adams and writer Denny O’Neil used their stories to bring back Batman has his roots as a detective in a world full of psychotic criminals and disturbing shadows. Together, O’Neil and Adams also created Ra’s Al Ghul, the immortal terrorist who became one of Batman’s iconic enemies, and his daughter Talia. Later, the characters served as key antagonists in Christopher Nolan’s first and third Batman movies, where they were played by Liam Neeson and Marion Cotillard.

Towards the end of the first round of x-men comics in the late 1960s, Adams drew another batch of acclaimed and influential stories. These issues, written by Roy Thomas, feature more dynamic layouts and bold Adams numbers, as well as amazing covers like this.

Back in DC, again with O’Neal, Adams helped transform The Green Lantern from a title also broadcast to one of the most important series of its time. Abandoning the cartoonish and supernatural bent of most previous The Green Lantern stories, they refocused the book on contemporary social issues like race, class, and drugs that were largely ignored by comic books of that era. Their run also featured John Stewart, only the second African-American hero ever featured in DC Comics. He remains a major DC character to this day.

A strong advocate for creators’ rights, Adams was also instrumental in helping Golden and Silver Age comic book writers and artists finally receive full credit for their work. Prior to his lobbying, Superman creators Jerry Siegel and Joe Shuster weren’t even credited with coming up with the character in the pages of DC Comics. (Today, any book that features Superman includes a mention of their names.)

In other words, Adams had a huge impact on the comics industry, both on the page and behind the scenes. The books he illustrated and the characters he created or modernized will be read and loved for generations to come.