Russell T Davies is to step down as executive producer of the BBC hit show Doctor Who.
Davies brought The Cult show back on to British television in 2005, breathing new life into the character and casting Christopher Eccleston as the time-travelling doctor.
Steven Moffat will succeed Davies as the lead writer and executive producer for the fifth series due to be aired in 2010.
Moffat has previously worked on the hit show and picked up a BAFTA for his writing on previous episodes.
"It's a huge honour to be following Russell into the best and the toughest job in television," he said.
Davies returned the praise of his successor, claiming: "It's been a delight and an honour working with Steven, and I can't wait to see where his extraordinary imagination takes the Doctor. Best of all, I get to be a viewer again, watching on a Saturday night."
Jane Tranter, controller of BBC Fiction, paid tribute to both men, saying: "As lead writer and executive producer, he has overseen the creative direction and detail of the 21st century re-launch of Doctor Who and we are delighted to have his continued presence on the specials over the next 18 months.
"But the challenge and excitement of the fifth series is now being handed to Steven Moffat. The Tardis couldn't be in safer hands. Steven's talents on both Doctor Who and beyond are well known. He is a writer of glittering brilliance, comedy and depth, with an extraordinary imagination and a unique voice."
Davies is set to remain in charge of the four special episodes to be broadcast in 2009.