Redstone, who served as executive chairman of National Amusements following its purchase of a controlling stake in Viacom in 1987, was also CEO when it merged with network broadcaster CBS Corp. in 2000 through his privately-controlled company. He remained executive chairman of both companies when they were split again in 2005, but then stepped down as the executive chairman of the merged entity that followed their reunion in February 2019.
“Sumner Redstone was a brilliant visionary, operator and dealmaker, who single-handedly transformed a family-owned drive-in theater company into a global media portfolio, said ViacomCBS CEO Bob Bakish. "He was a force of nature and fierce competitor, who leaves behind a profound legacy in both business and philanthropy. ViacomCBS will remember Sumner for his unparalleled passion to win, his endless intellectual curiosity, and his complete dedication to the company."
"We extend our deepest sympathies to the Redstone family today,” Bakish said.
ViacomCBS shares were marked 1.4% higher in pre-market trading Wednesday, but have fallen around 36% so far this year.
Born in Boston, Massachusetts in 1923, Redstone graduated from Harvard University i 1944 before serving as a 1st Lieutenant in the U.S. Army during the Second World War.
Redstone then attended Georgetown Law School, graduating in 1947, before joining National Amusements, a movie theater chain founded by his father, in 1954.
Redstone is survived by this daughter Shari, who is currently chairwoman of ViacomCBS after orchestrating the reunion of the two group's following years of legal battles with investors, as well as her father, in 2016.
"My father led an extraordinary life that not only shaped entertainment as we know it today, but created an incredible family legacy," Shari Redstone said in a statement. "Through it all, we shared a great love for one another and he was a wonderful father, grandfather and great-grandfather. I am so proud to be his daughter and I will miss him always.”