Matthew Winkler, founding editor-in-chief of Bloomberg News and one of the most skilled survivors in a tumultuous and ever-shifting media environment, has been kicked upstairs by the boss who hired him 25 years ago. Winkler’s replacement as editor-in-chief will be John Mickelthwait, the regarded top editor of The Economist, a publication the former New York City Mayor Michael Bloomberg has long admired. Winkler will assume the title of  Editor-in-Chief Emeritus, according to a memo to the staff from the owner.

Earlier this year, Bloomberg returned to the helm of Bloomberg LP, the financial services company of which the news operation is just one part, after ending his 12-year run as mayor. The first fallout from that move was the departure of his hand-picked CEO, Daniel Doctoroff, a former deputy in his administration.

Under Winkler’s leadership, Bloomberg has expanded the news operation into one of the world’s biggest and smartest. Occasional controversy developed along the way as questions arose about the sometimes intimate relationship between journalists and the larger company, whose main business is signing up users for the $2,000-a-month-plus terminals that provide sophisticated parsing of information for the financial industries.

Through it all, Winkler held firm to the top chair, in part through his close relationship with Bloomberg, who had hired him away from the Wall Street Journal to create the news division of his then-nascent company. Winkler’s own tenure was marked by sometimes embarrassing outbursts of anger in the newsroom that found their way onto websites trafficking in media gossip, as well as more serious assertions regarding his role in killing sensitive stories in foreign markets where the company was seeking to increase terminal sales. But he also was widely admired for his commitment to rigorous, concise reporting and breaking news.

“Hiring Matthew Winkler 25 years ago to create a news service that would allow Bloomberg to bypass the wire services and provide market-moving information more quickly to our customers was one of the best decisions I ever made,” Bloomberg wrote in his memo to the staff, “and it worked out better than either of us could have hoped.”

But, he continued, “I have always believed that organizations benefit from internal change, and that is one of the reasons I stepped away in 2001. Now, as I resume full-time leadership in the company in 2015, Matt will take on a new role as Editor-in-Chief Emeritus, working directly with me on strategic initiatives, while also conducting high-profile interviews of global newsmakers and bringing his insights and expertise to the most important stories.”

Bloomberg, a former bond trader, added that Mickelthwait’s “background makes him the perfect fit for the job. John began his career in banking at Chase Manhattan. He moved to The Economist in 1987 to become a finance correspondent and worked his way to the top. He has done an exceptional job leading The Economist into the digital age and expanding its audience.”

Disclosure: I came to Deadline.com after eight years as an editor, critic and reporter at Bloomberg News, when my department was disbanded. I had a great time there.