Nancy Gibbs, the first woman editor-in-chief of Time, is stepping down following a four-year run. The 57-year-old joined Time in 1985 as a fact-checker.

Nancy GibbsNancy Gibbs

Rich Battista, CEO of Time Inc., and Alan Murray, chief content officer, called her departure “the end of era” and promised that a successor will be named shortly.

“As editor, she successfully ushered Time into a new era, meeting the demands of growing digital and mobile audiences, as well as introducing the brand to new audiences while building on its tradition of excellent journalism. She is without doubt one of the most outstanding,” they wrote in a memo. “Nancy is one of a kind and cannot be replicated. But we plan to move quickly to name a new editor-in-chief. Nancy has built not only a remarkable legacy but also a remarkable news organization, and we are determined to maintain its power and relevance in the years ahead.”

Gibbs will remain as Time’s editorial director until yearend though Battista and Gibbs said in a memo they “hope to keep her involved with the company in various ways for many years to come.”