Charles F. Dolan, who founded some of the most influential media companies in the United States, including Home Box Office Inc. (HBO) and Cablevision Systems, died at the age of 98.

“It is with deep sadness that we announce the loss of our beloved father Charles Dolan, the visionary founder of HBO and Cablevision,” the family’s statement reads.

Dolan left behind a significant legacy in the cable television industry by creating HBO in 1972, Cablevision in 1973 and American Movie Classics in 1984.

He also founded News 12 in New York City, the first 24-hour cable local news channel in the United States.

Born in Cleveland, Dolan dropped out of John Carroll University in suburban Cleveland.

In 2015, the Dolan family sold Cablevision to European company Altice for nearly $18 billion.

At the time of his death, the Dolan family had a net worth of $5.4 billion, according to Forbes.