After a controversial media career spanning 7 decades, Rupert Murdoch is stepping down as chairman of both Fox Corporation and News Corp.

The 92-year-old billionaire will be replaced by his son Lachlan Murdoch as the solitary chair of News Corp. Lachlan is also set to continue his roles as both executive chair and chief executive of Fox. Rupert will be appointed chairman emeritus of each company.

Murdoch sent out a memo to his employees this morning explaining his reasoning in stepping down.

“The time is right for me to take on different roles, knowing that we have truly talented teams and a passionate, principled leader in Lachlan who will become sole chairman of both companies,” he said.

Throughout the memo, Murdoch took one last stab at certain sections of the media saying “self-serving bureaucracies” will try and silence anyone who questions them.

“But the battle for the freedom of speech and, ultimately, the freedom of thought, has never been more intense,” he said.

Despite the change in his job title, Murdoch insisted his involvement in his companies would not dissipate.

“In my new role, I can guarantee you that I will be involved every day in the contest of ideas,” he said. “I will be watching our broadcasts with a critical eye, reading our newspapers and websites and books with much interest, and reaching out to you with thoughts, ideas, and advice.”

His son Lachlan released a statement thanking his father for his contributions.

“On behalf of the Fox and Newscorp boards of directors, leadership teams, and all the shareholders who have benefited from his hard work, I congratulate my father on his remarkable 70-year career,” he said.

“We thank him for his vision, his pioneering spirit, his steadfast determination, and the enduring legacy he leaves to the companies he founded and countless people he has impacted.”

Murdoch began his media career from inheriting a newspaper from his father Keith, The News, in Adelaide in the 1950s.

10 years later he established The Australian newspaper, in addition to also purchasing his first British newspaper in The Sun.

In 1976 he bought The New York Post, and following that he obtained The Times newspaper in the 1980s. In 1985 Murdoch bought Twentieth Century Fox Film Corporation and five television channels from Metromedia, debuting the Fox network in the US the very next year.

Photo: Rupert Murdoch 2011 Shankbone by David Shankbone available HERE and used under a Creative Commons license. This image has not been modified.