Prince Harry has been tested for HIV - in a bid to encourage more members of the public to come forward and discover if they have the virus.
Harry, who has recently made highlighting the issue of HIV/Aids a major element of his public work, visited a sexual health clinic for the simple finger-prick procedure, which was broadcast on Facebook Live.
The Prince tested negative after he gave a small sample of blood at the Burrell Street centre in central London.
Harry had to wait a few moments while the sample was mixed with chemicals and poured into a test tray where a developing solution was added.
The negative result was indicated by a blue spot seen in the tray - if two spots had appeared he would have needed further tests to confirm if he was HIV positive.
With an estimated 11,000 people in the UK unaware they have the virus, Harry took the step of being publicly tested to help tackle the stigma surrounding the disease.
Ian Green, chief executive of Terrence Higgins Trust, called the broadcast a 'groundbreaking moment in the fight against HIV'.
As he waited for the test result to appear, Robert Palmer, a lead health adviser and psychosexual counsellor who carried out the procedure, asked the Prince: "You all right?" and Harry replied "I'm OK".
Mr Palmer said afterwards: "He was anxious, he said so, but everything was all right in the end."
Asked about the significance of a member of the Royal Family being tested for HIV, he said: "It means this is a test for everybody - it doesn't matter who you are, it's a good idea to have an HIV test."