Wadah Khanfar, until very recently the director-general of Al-Jazeera, is due in London this evening to deliver the James Cameron Memorial Lecture at City University. This is the first time a journalist from the Middle East has been invited to give the lecture (the year of the Arab Spring seemed an appropriate moment) and the first time that Khanfar has been in London since he suddenly announced that he was stepping down from running Al-Jazeera.

To get an idea of the importance of satellite television in general – and of Al-Jazeera in particular – in this year’s events in Tunisia, Egypt, Syria and Bahrain take a look at the annual Strategic Survey of the Institute of Strategic Studies (the relevant section starts at p97). I have a fair idea of who wrote the (unsigned) analysis and she is very expert. There have been many analyses of the influence of social networks and satellite television on the Arab revolutions. Because the IISS survey is sober and careful, its carefully weighed evidence about the influence of cross-border broadcasters counts for more. A slightly less sober (but well-rated by insiders) account of Al-Jazeera’s sudden global fame from GQ is here.

We still don’t know exactly why Khanfar left his job: this is his explanation and this is a summary of the rumours. Khanfar is a journalist; he was replaced by a member of the Qatari royal family previously working in a state oil and gas compnay. All of the above (significance, reasons for departure) in this piece from the Columbia Journalism Review. We may learn more this evening; I will report back tomorrow.