Washington Post owner Jeff Bezos on Wednesday announced a “significant shift” to the publisher’s opinion page that led David Shipley, the paper’s editorial page editor, to leave the paper. The changes upended precedent and rattled a media company that has already been shaken by years of turmoil and leadership turnover.

In an email and social media post, Jeff Bezos outlines dramatic changes to The Washington Post’s opinions section, and announces that opinions editor David Shipley has resigned.

Jeff Bezos, the billionaire owner of the Washington Post, is making changes to the newspaper’s opinion pages to limit what he described as viewpoints opposing “personal liberties and free markets.”