Apple said on Monday that John Ternus is succeeding Tim Cook as CEO, with Cook assuming the role of executive chairman on Sept. 1.

Ternus, a senior vice president of hardware engineering, will join Apple’s board of directors when he becomes chief. Apple’s non-executive chairman Arthur Levinson will become the iPhone-maker’s lead independent director on that date.

“Cook will continue in his role as CEO through the summer as he works closely with Ternus on a smooth transition,” Apple said in a press release.

It’s the first CEO transition for Apple since Cook succeeded Steve Jobs at the helm in 2011, shortly before Jobs’ death.

“It has been the greatest privilege of my life to be the CEO of Apple and to have been trusted to lead such an extraordinary company,” Cook said in a statement. “I love Apple with all of my being, and I am so grateful to have had the opportunity to work with a team of such ingenious, innovative, creative, and deeply caring people who have been unwavering in their dedication to enriching the lives of our customers and creating the best products and services in the world.”

Apple’s market cap increased by roughly 24-fold on Cook’s watch, closing on Monday at $4 trillion.

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