Ex-BBC and New York Times boss Sir Mark Thompson has been appointed to lead CNN following a series of crises and falling ratings at the US news network.
Sir Mark replaces Chris Licht, who struggled to stabilise CNN in his 13 months as chairman and CEO.
Sir Mark must also guide CNN during the 2024 US presidential election.
That challenge will coincide with coverage of criminal charges against Donald Trump.
The network has had a famously tempestuous relationship with the former US president, who unsuccessfully tried to sue CNN for defamation, claiming it had created a "false and incendiary association" between him and Adolf Hitler following the last election.
A CNN interview with Mr Trump in May was widely criticised, including by the network's own Christiane Amanpour. Mr Licht stepped down weeks later.
CNN's previous boss Jeff Zucker had been forced to resign in February 2022 after failing to disclose a romantic relationship with a senior executive.
David Zaslav, chief executive of parent company Warner Bros Discovery, described Sir Mark as "a formidable force for CNN and journalism at this pivotal time".
He added: "Mark is a true innovator who has transformed for the digital age two of the world's most respected news organizations."
The British executive was director general of the BBC from 2004 to 2012, and is credited with reviving the fortunes of the New York Times by boosting digital subscriptions as president and CEO from 2012 to 2020.
"I can't wait to roll up my sleeves and get down to work with my new colleagues to build a successful future for CNN," Sir Mark said.
His appointment comes days after Warner Bros Discovery announced a new attempt at launching a CNN streaming service, CNN Max, which will combine existing shows with online-only programming.
CNN's cable TV ratings have been dropping faster than those of its competitors, according to official figures quoted by the Associated Press earlier this year.