|Khanfar began as a correspondent with Al Jazeera in locations such as Africa, Afghanistan and Iraq
Al Jazeera's director general, Wadah Khanfar, has stepped down after eight years as the network's top executive.
Khanfar, who announced his decision on Tuesday, said he had been discussing his decision to step down with Sheikh Hamad bin Thamer Al Thani, the chairman of the board, for some time.
In a farewell note to Al Jazeera staff, Khanfar mentioned that upon his appointment he spoke with the chairman and they set the goal to establish Al Jazeera as a global media leader.
In final discussions, they agreed that this target had been met and that the organisation is in a strong position going forward.
Khanfar, who began as a correspondent with the network in locations such as Africa, Afghanistan and Iraq, said his time in the field had taught him the importance of a free press with the human being at the core of its agenda.
An Al Jazeera spokesman said: "Wadah Khanfar had made outstanding contributions to Al Jazeera and journalism worldwide.
"We all recognise his commitment to courageous reporting and want to continue to build upon those achievements."
Sheikh Ahmed bin Jassim bin Mohammed Al Thani has been appointed as new director general.
'Voice of the voiceless'
In a note to staff on Tuesday, Khanfar said: "When we launched in 1996 'media independence' was a contradiction in terms.
"State media was prevalent and was blatantly used for propaganda and misinformation. Within such an environment the public probably doubted that Al Jazeera would fulfill its promise of independent journalism.
Khanfar talks about his optimism for the Arab Spring
"We managed to pleasantly surprise them by exceeding all expectations.
"Yet we remained steadfast in our editorial policy – in fact, each attempt to silence us further emboldened us and increased our resolve.
"Al Jazeera gained the trust of its audience through consistently speaking truth to power, and channelling peoples' aspirations for dignity and freedom.
"Our audience quickly saw that Al Jazeera was of them and their world - it was not a foreign imposition nor did it seek to impose a partisan agenda. We were trusted to be objective and to be the voice of the voiceless.
"This newsroom showed the world the first images of the Asian Tsunami and of the famine in Niger. In 2011, the eyes of the world watched the aspirations of millions unfold as our newsrooms broadcast, tweeted and published the events unfolding in the liberation squares from Sidi Bouzid to Jisr Al-Shughur.
"The coverage of these revolutions is ongoing, and we continue to report the fight of the youth to achieve dignity and freedom from tyranny and dictatorship.
"I am fortunate to have had eight years working with an outstanding group of professionals. Today, Al Jazeera stands as a mature organisation and I am confident that the organisation will continue to maintain its trailblazing path."
Khanfar offered his "most profound gratitude" to his staff and the loyal audience of Al Jazeera.