Baroness Butler-Sloss is to step down in June as coroner for the inquests into the death of Princess Diana and Dodi Al Fayed, it has been announced.
Baroness Butler-Sloss was the second coroner in the role
Lady Butler-Sloss said she lacked the experience required to deal with an inquest with a jury.
Lord Justice Scott Baker will take over as coroner for the inquests, which are expected to take place in October.
The princess died in a car crash in 1997 in the Pont D'Alma tunnel in Paris along with Mr Al Fayed.
Lady Butler-Sloss said in a statement: "This was a decision I took in the interests of the inquests after a great deal of thought and reflection.
"These inquests now require a jury, and I do not have the degree of experience of jury cases that I feel is necessary and appropriate for presiding over inquests of this level of public interest.
"I must stress this does not require a fresh start for the inquests - I will continue to preside over pre-inquest hearings until Lord Justice Scott Baker takes up the appointment in June.
"This will ensure the inquests' momentum is maintained while he will have the opportunity to familiarise himself with the voluminous paperwork associated with the inquests."
BBC royal correspondent June Kelly said Lady Butler-Sloss' decision was a "bombshell".
"This really is a saga now and the fact that you are now going to be on your third coroner I don't think anyone could have foreseen this," she said.
The former Royal press secretary, Dickie Arbiter, told the BBC he was not surprised by Lady Butler-Sloss' resignation.
"She's had her credibility somewhat dented in the first instance since having said no, she's not going to go for a jury and then that being challenged and having to give way and yes, there will be a jury.
"So I think it was just a matter of time. And it's good to see that she's going to hang on there until the next coroner joins in."
In July last year, the then royal coroner Michael Burgess quit the inquests, blaming a "heavy and constant" workload.
Lady Butler-Sloss, Britain's former top woman judge, took on the role in September.
LORD JUSTICE SCOTT BAKER
Became High Court Judge in Family Division in 1988
Transferred to the Queen's Bench Division in 1992
Became a Lord Justice of Appeal in 2002.
Was a member of the Parole Board from 1999 to 2002
Lord Justice Scott Baker is one of Britain's most experienced judges
The hearings were originally to take place in May but were put back until October after lawyers for Mohammed Al Fayed, Dodi's father, requested more time to allow them to prepare.
Harrods department store owner Mr Al Fayed won a High Court ruling that the inquests should be heard before a jury.
The decision overturned a decision by Lady Butler-Sloss that she would sit alone.
Mr Al Fayed alleges the August 1997 Paris road crash which claimed the couple's lives was part of a secret plot by the British establishment.
The hearings are expected to last between four and eight months.
A three-year inquiry conducted by former Metropolitan Police chief Lord Stevens concluded that Princess Diana had died in a tragic accident and that there had been no conspiracy and no cover-up.