A special service is being held at Westminster Abbey on Wednesday morning to mark 75 years of the National Health Service.
The service, at 11am, will be attended by the Duke and Duchess of Edinburgh as well as around 1,500 NHS staff, and senior government and political leaders.
During the service, winning images from a photography competition to mark the anniversary will be on display and an address will be given by NHS Chief Executive Amanda Pritchard.
Prayers will be read by Health Secretary Steve Barclay, Chief Nurse Dame Ruth May, and Richard Webb-Stevens, a paramedic who was first on the scene of the Westminster Bridge terror attack.
Dame Ruth said it would be "a fantastic honour" to celebrate the NHS' 75th birthday at Westminster Abbey.
"The NHS has truly been built upon the millions of hardworking NHS staff and volunteers who have shaped its course over the last three quarters of a century, constantly innovating and adapting to the new challenges they have faced – most recently the Covid-19 pandemic that has affected all our lives – to care for generation after generation," she said.
"As well as the service, there are countless events and special moments over the next week which everyone can get involved with, whether it be local parkrun events or the lighting up of over 150 landmark sites across the country, with many opportunities to not only look back on all that the NHS has achieved but also to look ahead to what new opportunities and innovations we can grasp in our next 75 years."
Mr Barclay said:"As we mark this milestone, we can be so proud of everything the NHS has achieved over the last 75 years.
"From its foundation in the aftermath of World War II, to the world's first test tube baby and administering the first Covid vaccine – the NHS is an institution that deserves its title as a national treasure.
"I want to thank all the staff who have ever worked in the NHS, from the doctors and nurses caring for our loved ones, to the cleaners and porters keeping our hospitals in order, and our social care workers, paramedics, physiotherapists and many more who do an outstanding job, each and every day.
"As we look ahead to the future, I am focused on investing in our workforce to ensure it is properly resourced and adopting the latest technology so we can deliver on our commitment to cut waiting lists so the NHS can continue to provide the best care for patients."
Among the special guests are 91-year-old Enid Richmond, who was one of the first people to work in the NHS as a junior clerical worker, and Dame Elizabeth Anionwu, the UK's first sickle cell nurse.
Another is May Parsons, the nurse who delivered the world's first Covid 19 vaccine outside of a clinical trial in December 2020. She will carry the George Cross, which she received from the Queen last year, into the Abbey in a procession.
She said that being part of the procession "will be another enormous privilege and 'pinch-me' moment".
"The service and other activities provide NHS staff and volunteers, and everyone else across the country too, with a perfect opportunity to reflect on what the health service has achieved over the last 75 years and how far we have come," she said.
"For me, it is a wonderful opportunity to reflect on the moment I delivered the first vaccination outside of a trial to the brilliant Maggie Keenan, something which kick-started one of the highlights of NHS history – the hope the world-leading vaccination programme gave the world – which helped get the country back to normal and saved so many lives."
Later in the day, landmarks including Salisbury Cathedral, the London Eye and Blackpool Tower will be lit up in blue to mark the 75th anniversary.
A special NHS parkrun will be held this Saturday and the Royal Mint has issued a 50p coin for the occasion, with funds going to NHS Charities Together.
On Wednesday night, actor Tom Hardy will read Zog and the Flying Doctors on CBeebies Bedtime Stories.
