A new pill is to be made available in Sheffield to help prevent the spread of HIV.
Patients will be able to access the 'transformative' HIV prevention treatment from September following a High Court battle over funding the drug on the NHS.
NHS England announced that pre-exposure prophylaxis (PrEP), a pill taken before sex which has been shown to reduce the risk of infection in high-risk individuals by around 86 per cent, will now be provided by the health service as part of an initial three-year trial to an estimated 10,000 people.
It agreed to fund the trial after the Court of Appeal upheld a High Court ruling last year, which said the NHS had the power to pay for PrEP despite its claims that local authorities should fund it.
The move announced on Thursday was hailed as a 'major new intervention' by NHS England chief executive Simon Stevens while the National Aids Trust described it as a 'pivotal moment'.
Sexual health clinics in Sheffield, London, Brighton, Manchester and Liverpool will be among the first to start enrolling people, with more clinics joining in October before full implementation across England by April 2018.
Clinics will identify eligible participants who consent to the trial, including men, women, transgender people, and individuals who have a partner whose HIV status is not known to be controlled by anti-retroviral treatment.
People living in and registered with a GP in England will also be able to enrol for potential participation at their local sexual health clinic
The programme, which will cost £10 million, is designed to asses the full potential of PrEP by gathering clinical evidence on how it is targeted, taken up and implemented on a large scale.
Mr Stevens said: "This major new intervention should complement and supercharge the wide-ranging and increasingly successful effort to prevent HIV.
"It's another milestone in more than three decades' worth of progress in tackling one of humanity's major health challenges."
Deborah Gold, chief executive at National Aids Trust, said: "This is a pivotal moment in the fight against HIV.
"PrEP, if targeted properly at those in need and at risk, offers the possibility of transforming the English HIV epidemic.
"From September, people at high risk of HIV will have access via this NHS-funded trial in England to an empowering new tool that is truly individually controlled and not subject to negotiation with a partner, leading to the improvement of many, many lives.
"We warmly welcome this announcement."
Ian Green, chief executive of the Terrence Higgins Trust, said: "The priority must now be to make sure that the trial is rolled out speedily across the country, and that no-one at risk of HIV is left behind.
"Now that the PrEP trial drug has been procured, we're well on the way to protecting over 10,000 people at risk of HIV."
Shadow public health minister Sharon Hodgson said: "The start of the PrEP trial is welcome and long overdue after months of delays and heel-dragging by the Government.
"The evidence shows just how transformative this drug can be as part of our approach to HIV prevention and ending the transmission of this life-changing infection.
"This trial will take us one step closer to fully understanding the benefits of PrEP.
"Now it is important that this trial is rolled out as quickly as possible across the country to protect individuals who are exposed to HIV and help take us one step closer to ending the spread of HIV in society."