John Cleverly Cartney lead the group known as The Hellfire Club, which wanted to overthrow the crown. However, The Avengers, John Steed and Emma Peel defeated him and Cartney apparently fell to his death.
The Hellfire Club and its nefarious leader was created for the '60s British TV series The Avengers episode titled "A Touch of Brimstone". He was played by Peter Wyngarde, who was also one of the number twos on The Prisoner among other roles.
In 2012, Mark Waid , took up Cartney's story for Steed and Mrs. Peel's new ongoing series.
After a number of spy's deaths, Steed and Emma go to investigate the Hellfire Club. They meet Ian Landowne Dunderdale Cartney, astro secretary of the new Hellfire Club. However, they soon learn nothing is what it seems and the club is back it's old tricks. They also find out that Cartney is not dead at all.