Alan Rusbridger, the editor-in-chief of The Guardian, announced Wednesday in a tweetstorm he will leave his role at the news organization to become chair of The Scott Trust.

Scott Trust is the "sole shareholder in Guardian Media Group," established in 1936 to "safeguard the journalistic freedom" of the paper, according to its website.

Rusbridger will leave The Guardian next summer, after the news organization finds his replacement, according to The Guardian. He will join The Scott Trust the following year.

Under Rusbridger's leadership, The Guardian won its first Pulitzer Prize for revealing the scope of widespread surveillance by the National Security Agency.

For his leadership on those stories, Rusbridger was also awarded the European Press Prize. After he accepted the award, Rusbridger held one of the hard drives the British government made Guardian staffers destroy after the news organization revealed it was in possession of documents leaked by NSA contractor Edward Snowden.

Rusbridger has been editor of The Guardian since 1995, according to his website. He began his career as a reporter at the Cambridge Evening News before joining The Guardian, where he worked as a features writer and held a variety of editing roles.

Here's the full release from The Guardian:

The Scott Trust, which safeguards the editorial future and independence of the Guardian, has appointed Alan Rusbridger, editor-in-chief of Guardian News & Media, to succeed Dame Liz Forgan as its chair.

Rusbridger will step down as editor-in-chief in Summer 2015, following the appointment of his successor. He will become chair of The Scott Trust in 2016, when Liz Forgan reaches the end of her term.

Liz Forgan said: “Alan has been the outstanding editor of his generation. Fully embracing the opportunities of the digital age, he has built on the best traditions of his distinguished predecessors, transforming the Guardian from a print-only national newspaper into the world’s leading quality newspaper website.

“We are delighted that The Scott Trust and the wider Group will continue to benefit from his experience, overseeing the independent body that guarantees the editorial integrity and commercial future of the Guardian.”

Under Rusbridger’s editorship, the Guardian has expanded from a UK-only newspaper to an international, multi-platform media organisation and one of the leading quality newspaper websites in the world.

Earlier this year, the Guardian was awarded the highest accolade in US journalism, winning the Pulitzer Prize for public service for its ground-breaking articles on the National Security Agency’s surveillance activities based on the leaks of Edward Snowden. It was also named Newspaper of the Year at the UK Press Awards for its reporting on government surveillance. Its website, theguardian.com, was also awarded the digital award. In addition, the Guardian’s journalism has, in the past 12 months, been recognized with an Emmy, “The Special Award” at the European Press Prize, a Polk award, the Right Livelihood Award in Sweden, and scoop of the year at the 59th Walkley awards for excellence in journalism

Alan Rusbridger said: “In global journalism, there are a handful of roles that have the capability to redefine our industry. I am privileged to have held one of those roles for 20 years, a period in which successful newspapers have become global content providers, reaching audiences in dramatically new and valuable ways.

“I am honoured to succeed the quite brilliant Liz Forgan as chair of The Scott Trust, preserving the independent editorial values and the long-term financial stability upon which our future depends. We have strong future leaders in place with unparalleled news and digital experience, and I know that our journalism will be in the best possible hands.”

The process by which The Scott Trust will appoint the new editor-in-chief will be announced in due course.

Neil Berkett, Chairman of Guardian Media Group, said: “Alan has set the standard for journalistic leadership in the digital age. His appointment to lead The Scott Trust coincides with rapidly rising readership, continued innovation and secure finances at the Guardian. His successor will inherit a global media organisation in very strong health and with clear prospects for further growth.”