The BBC has appointed former Google executive Matt Brittin as its new director general. Brittin will replace outgoing director general Tim Davie. He resigned last year in the wake of revelations about the editing of a Panorama documentary about Donald Trump and board disagreements over how it should be handled. Brittin’s appointment comes at a critical moment, as the broadcaster prepares to renew its royal charter. This is the constitutional basis for the BBC’s existence, which sets out its mission and public purposes. It is traditionally renewed once a decade to make sure the BBC keeps up to date with political and technological changes. Because the renewal process is run by the government of the day, it can involve difficult conversations with ministers who – while acknowledging the BBC’s independence – can insist on major changes. Despite some challenging political environments, each charter renewal has generally resulted in an evolution from previous years. The BBC has moved from radio to TV, from analogue to digital and online. But this time around feels more existential. In …