Over the past 25 years, Channel 4 has been predominantly a factual channel, with provocative and challenging current affairs at the core of its broadcasting for much of the time.

Not surprisingly, the area has generated a lot of heat – as this year’s debates about radical Islamic preaching depicted by Undercover Mosque and the truth about global warming again demonstrated in spades.

But what the history I’ve written also shows is that in the early years, current affairs was a minefield, creating such extreme tensions between the founder, Jeremy Isaacs and his chairman, Edmund Dell, that it seemed the youthful company would be torn apart. Or that one of them would have to go.