7 Moments That Almost Killed Doctor Who
2. David Tennant's Departure
When the series relaunched in 2005 with Christopher Eccleston as the 9th Doctor, it managed to score big in terms of ratings, and the series was reborn. Unfortunately, Eccleston only signed on to do the one series, and that meant he needed to be replaced by the inimitable David Tennant.
While Eccleston managed to build a great deal of buzz around the character, Tennant's 10th Doctor managed to draw in millions of fans. His performance was amazing, and he stuck around for several years before deciding it was time to leave the TARDIS to pursue other projects.
At this time, the word "cancel" was being spoken a lot because it wasn't just Tennant leaving. Russell T. Davies, the showrunner who breathed new life into Doctor Who, was departing as well. With their departure, the BBC was concerned about the series' long term prospects, and it was at risk of being canceled.
Fortunately, Davies was replaced with Steven Moffat, and Matt Smith took over as the Doctor. According to Moffat, it was Davies who saved the show as he was departing. He told the BBC, "You are not allowed to end it," and it seems they were listening.