Prince Philip has been taken to hospital for a “planned visit” on advice of “His Royal Highness’ Doctor”.

The Duke of Edinburgh travelled from Norfolk this morning to the King Edward VII Hospital in London for observation and treatment in relation to a pre-existing condition as a “precaution”, Buckingham Palace said.

Prince Philip, 98, left Sandringham, where he spends much of his time since retiring from public life in August 2017.

The announcement came as the Queen arrived at the Norfolk estate after travelling from the capital on Friday.

A Buckingham Palace statement said: “The Duke of Edinburgh travelled from Norfolk this morning to the King Edward VII Hospital in London for observation and treatment in relation to a pre-existing condition.

Queen Elizabeth II and Prince Philip over the years: In pictures Show all 32 1 /32 Queen Elizabeth II and Prince Philip over the years: In pictures Queen Elizabeth II and Prince Philip over the years: In pictures The then-Princess Elizabeth and Philip Mountbatten pose for a photograph on the day their engagement is announced alongside Princess Margaret (9 July 1947) AFP via Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The future Queen Elizabeth II and Philip, Duke of Edinburgh are photographed together on their wedding day at Buckingham Palace (20 November 1947) AFP via Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The newlywed couple enjoy their honeymoon in Broadlands estate, Hampshire (25 November 1947) AFP via Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The couple dance the samba during a ball organised by the Royal Navy (18 December 195) AFP via Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The future monarch and Prince Philip pose with their firstborn child, a baby Prince Charles (undated photograph) AFP via Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The couple are photographed with their children Prince Charles and Princess Anne (circa 1951) AFP via Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures Queen Elizabeth II and Prince Philip wave to the crowd on the day of the monarch's coronation (2 June 1953) AFP via Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The royal couple ride on horses, the Queen on her horse 'Winston', during the Trooping the Colour ceremony to mark the monarch's official birthday (12 June 1953) Photo by STRINGER/INTERCONTINENTALE/AFP via Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The Queen and the Duke of Edinburgh attend ceremonies to mark the opening of Parliament in Ottawa, Canada (14 October 1957) ARNOLD SACHS/AFP via Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The couple smile as they watch a cricket match together at Highclere Castle, Hampshire (3 August 1958) Photo by Victor Blackman/Daily Express/Hulton Archive/Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The Queen and Prince Philip depart Manchester by train (24 May 1961) Photo by Fox Photos/Hulton Archive/Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The royal couple laugh as they watch Susu dancers during their visit to the Northern Province of Sierra Leone (4 December 1961) STRINGER/AFP via Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures Queen Elizabeth II and Prince Philip are photographed at Ascot (June 1967) Photo credit should read STRINGER/AFP via Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The couple walk alongside their eldest child, Prince Charles, during his Prince of Wales investiture ceremony at Caenarvon Castle, Wales (2 July 1969) Photo by Dennis Oulds/Central Press/Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The Queen and the Duke of Edinburgh visit the Great Wall of China (October 1986) Photo credit should read -/AFP via Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The couple pose for an official portrait taken at Buckingham Palace (June 1987) AFP via Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The royals speak with schoolchildren in Hamilton, Bermuda during a 21-day visit to Latin America, the Caribbean and Bermuda (9 March 1994) LUKE FRAZZA/AFP via Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The Queen and the Duke of Edinburgh leave Westminster Abbey following the funeral ceremony of the Queen Mother (9 April 2002) FRANCOIS GUILLOT/AFP via Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The Queen waves as she and Prince Philip leave Manchester stadium following the closing of the XVII Commonwealth Games (4 August 2002) Odd Andersen/AFP via Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The royal couple wave goodbye as they board their plane at Abuja airport, Nigeria (6 December 2003) AFP via Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The Queen, the Duke of Edinburgh and other members of the royal family stand on the balcony at Buckingham Palace to watch the flypast on National Commemoration Day (10 July 2005) Photo by Daniel Berehulak/Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The couple wear protective eyewear as they take part in a tour as part of the opening of University College Hospital (20 October 2005) Photo by Pool/Michael Dunlea/Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The Queen and Prince Philip are photographed at Broadlands, Hampshire shortly before celebrating their diamond wedding anniversary (18 November 2007) FIONA HANSON/AFP via Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The royal couple laugh as they watch the games during the Annual Braemar Highland Gathering in Braemar, Scotland (6 September 2008) Photo by Chris Jackson/Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures Queen Elizabeth II and the Duke of Edinburgh don 3D glasses during a visit to the University of Sheffield Advanced Manufacturing Research Centre (18 November 2010) Photo by John Giles - WPA Pool/Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The royal couple wave as they arrive on Ladies Day at Royal Ascot (16 June 2011) Photo by Dan Kitwood/Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The Queen and the Duke of Edinburgh smile as they say goodbye to Irish President Michael D Higgins and his wife Sabina at Windsor Castle (11 April 2014) Photo by Leon Neal-WPA Pool/Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures Prince Philip holds the monarch's hand as they leave the Service of Commemoration for troops who were stationed in Afghanistan (13 March 2015) Photo by Chris Jackson/Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The couple sit next to one another in the House of Lords during the Queen's Speech at the Palace of Westminster (27 May 2015) Photo by Alastair Grant/WPA Pool/Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures Queen Elizabeth II waves to the crowds on the day of her 90th birthday (21 April 2016) Photo by Chris Jackson/Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The Queen and the Duke of Edinburgh sit together in a carriage during the Trooping the Colour ceremony on The Mall (11 June 2016) Photo by Ben A. Pruchnie/Getty Images Queen Elizabeth II and Prince Philip over the years: In pictures The royal couple feed Donna the elephant during a visit to the Elephant Centre at the ZSL Whipsnade Zoo (11 April 2017) Photo by Chris Jackson/Getty Images

“The admission is a precautionary measure, on the advice of His Royal Highness’ Doctor.”

The Duke is expected to be in hospital for a few days.

He was not taken by ambulance and it was a planned admission.

Since his retirement, the Duke has reportedly remained active despite his health condition.

He missed the royal Christmas services in 2011 after it was revealed he was recovering from emergency surgery after suffering from a blocked artery.

Although he made a quick recovery, he was hospitalised again in 2017 after becoming ill with an infection linked to his pre-existing heart condition.

In April 2018 he was admitted to London’s King Edward VII Hospital to undergo a hip replacement.

The Duke has also missed several public events in previous weeks before the operation including an Easter service.

The Independent contacted Buckingham Palace for comment. They couldn’t ”go into details about the nature of the Duke’s condition” but they stressed that “the Queen has not changed her plans” due to the hospital admission.