Prince Philip has spent a second night in hospital after being admitted earlier this week as a “precautionary measure” following complaints that he was feeling unwell.
Buckingham Palace did not issue an update on the Duke of Edinburgh’s health when contacted by CNN on Thursday.
The 99-year-old husband of Queen Elizabeth was admitted to King Edward VII Hospital in London on Tuesday evening, Buckingham Palace said in a press release, issued Wednesday.
According to a Royal source, it was not an emergency admission and the Duke traveled to hospital by car and walked in unaided. The source added that the illness was not Covid-19 related.

Police stand guard outisde the entrance to King Edward VII hospital in central London where Prince Philip was admitted on Tuesday.
The Buckingham Palace press release on Wednesday said the Duke’s admission was a “precautionary measure” taken on the advice of his doctor after the Prince was “feeling unwell.”
“The Duke is expected to remain in hospital for a few days of observation and rest,” the press release added.

Photos: Prince Philip: Decades in public life

Photos: Prince Philip: Decades in public life
Britain’s Prince Philip, the Duke of Edinburgh, poses in his military dress uniform circa 1990.
Hide Caption
1 of 48

Photos: Prince Philip: Decades in public life
Prince Philip was born into the royal families of Greece and Denmark. His family left Greece in 1922 and settled in Paris after his uncle, King Constantine I, was overthrown.
Hide Caption
2 of 48

Photos: Prince Philip: Decades in public life
Prince Philip is dressed for a production of “Macbeth” while attending school in Scotland in July 1935.
Hide Caption
3 of 48

Photos: Prince Philip: Decades in public life
Prince Philip is the youngest of five children and the only son. After his parents’ separation in 1930, he was sent to England and raised there by his maternal grandmother and uncle.
Hide Caption
4 of 48

Photos: Prince Philip: Decades in public life
Prince Philip sits with his fiancee, Princess Elizabeth, in July 1947. He had become a naturalized British citizen and a commoner, using the surname Mountbatten, an English translation of his mother’s maiden name. He was also an officer of the British Royal Navy and fought in World War II.
Hide Caption
5 of 48

Photos: Prince Philip: Decades in public life
Prince Philip and Princess Elizabeth married in November 1947.
Hide Caption
6 of 48

Photos: Prince Philip: Decades in public life
Prince Philip plays in a village cricket match in July 1949.
Hide Caption
7 of 48

Photos: Prince Philip: Decades in public life
Philip and Elizabeth hold their children Prince Charles and Princess Anne in August 1951.
Hide Caption
8 of 48

Photos: Prince Philip: Decades in public life
Prince Philip and Princess Elizabeth dance in Ottawa in October 1951.
Hide Caption
9 of 48

Photos: Prince Philip: Decades in public life
Prince Philip and Princess Elizabeth were on a tour of the commonwealth when her father, King George VI, died on February 6, 1952. She was next in line for the throne.
Hide Caption
10 of 48

Photos: Prince Philip: Decades in public life
Prince Philip waves from the balcony of Buckingham Palace after his wife’s coronation in June 1953.
Hide Caption
11 of 48

Photos: Prince Philip: Decades in public life
Prince Philip sails during the Cowes Regatta in August 1962.
Hide Caption
12 of 48

Photos: Prince Philip: Decades in public life
Prince Philip laughs as the Beatles fight over the Carl Alan Award he presented to the band in March 1964.
Hide Caption
13 of 48

Photos: Prince Philip: Decades in public life
The Queen and Prince Philip, accompanied by sons Prince Andrew and Prince Edward, wave from a Buckingham Palace balcony during a parade in June 1964.
Hide Caption
14 of 48

Photos: Prince Philip: Decades in public life
The royal couple return to Buckingham Palace after a ceremony in June 1965.
Hide Caption
15 of 48

Photos: Prince Philip: Decades in public life
The Queen and Prince Philip leave Westminster Abbey in April 1966.
Hide Caption
16 of 48

Photos: Prince Philip: Decades in public life
Prince Philip competes in a bicycle polo match in August 1967.
Hide Caption
17 of 48

Photos: Prince Philip: Decades in public life
Prince Philip paints during the filming of the documentary “Royal Family” in 1969.
Hide Caption
18 of 48

Photos: Prince Philip: Decades in public life
Prince Philip and his daughter, Princess Anne, prepare a barbecue on the Balmoral Castle estate in August 1972.
Hide Caption
19 of 48

Photos: Prince Philip: Decades in public life
The Queen and Prince Philip attend the Royal Windsor Horse Show in April 1976.
Hide Caption
20 of 48

Photos: Prince Philip: Decades in public life
Prince Philip takes part in the World Carriage Driving Championships in 1980.
Hide Caption
21 of 48

Photos: Prince Philip: Decades in public life
Prince Phillip fishes in a Scottish loch in 1993.
Hide Caption
22 of 48

Photos: Prince Philip: Decades in public life
Prince Phillip hunts at the Sandringham estate in 1994.
Hide Caption
23 of 48

Photos: Prince Philip: Decades in public life
Prince Phillip tours the London Stock Exchange in 1998.
Hide Caption
24 of 48

Photos: Prince Philip: Decades in public life
Former South African President Nelson Mandela chats with Prince Philip in November 2000.
Hide Caption
25 of 48

Photos: Prince Philip: Decades in public life
Prince Philip rides a mini motorbike at the Royal Windsor Horse Show in May 2005.
Hide Caption
26 of 48

Photos: Prince Philip: Decades in public life
Prince Philip, the Duke of Edinburgh, attends a Commonwealth Day observance in London in 2011.
Hide Caption
27 of 48

Photos: Prince Philip: Decades in public life
The Queen and Prince Philip attend the annual Trooping the Colour ceremony in June 2011.
Hide Caption
28 of 48

Photos: Prince Philip: Decades in public life
Prince Philip visits Sherborne Abbey during his wife’s Diamond Jubilee tour in May 2012.
Hide Caption
29 of 48

Photos: Prince Philip: Decades in public life
The Queen presents Prince Philip with New Zealand’s highest honor, the Order of New Zealand, at Buckingham Palace in June 2013.
Hide Caption
30 of 48

Photos: Prince Philip: Decades in public life
Prince Philip visits the 1st Battalion of the Grenadier Guards in February 2014.
Hide Caption
31 of 48

Photos: Prince Philip: Decades in public life
The royal couple arrives at the Royal Ascot horse races in June 2014.
Hide Caption
32 of 48

Photos: Prince Philip: Decades in public life
Prince Philip signs the guest book at Hillsborough Castle in Belfast, Northern Ireland, in June 2014.
Hide Caption
33 of 48

Photos: Prince Philip: Decades in public life
Prince Philip smiles as he visits an Auxiliary Air Force squadron in Edinburgh, Scotland, in July 2015.
Hide Caption
34 of 48

Photos: Prince Philip: Decades in public life
Prince Phillip and his grandson Prince Harry attend the Rugby World Cup final in October 2015.
Hide Caption
35 of 48

Photos: Prince Philip: Decades in public life
The Queen and Prince Philip wave to guests in June 2016, during celebrations for her 90th birthday.
Hide Caption
36 of 48

Photos: Prince Philip: Decades in public life
Prince Philip feeds a banana to an elephant in Dunstable, England, in April 2017.
Hide Caption
37 of 48

Photos: Prince Philip: Decades in public life
Prince Philip talks to schoolchildren in May 2017 during a visit to Lord’s cricket ground in London. He opened the venue’s new Warner Stand.
Hide Caption
38 of 48

Photos: Prince Philip: Decades in public life
Prince Philip makes his final public appearance before his retirement in August 2017, attending a parade of the Royal Marines at Buckingham Palace. The event also marked an end to Philip’s 64 years as captain general, the ceremonial leader of the Royal Marines.
Hide Caption
39 of 48

Photos: Prince Philip: Decades in public life
This portrait, painted by Ralph Heimans, shows Prince Philip in the Grand Corridor of Windsor Castle. It was unveiled in December 2017.
Hide Caption
40 of 48

Photos: Prince Philip: Decades in public life
Prince Philip attends the wedding of his grandson Prince Harry and Meghan Markle in May 2018.
Hide Caption
41 of 48

Photos: Prince Philip: Decades in public life
Prince Philip poses with the wedding party after Harry and Meghan’s wedding in May 2018.
Hide Caption
42 of 48

Photos: Prince Philip: Decades in public life
Queen Elizabeth and Prince Philip attend a polo match in Egham, England, in June 2018.
Hide Caption
43 of 48

Photos: Prince Philip: Decades in public life
Prince Philip is seen at the wedding of his granddaughter Princess Eugenie and Jack Brooksbank in October 2018.
Hide Caption
44 of 48

Photos: Prince Philip: Decades in public life
Prince Philip speaks with Sir David Attenborough ahead of an Order of Merit luncheon in May 2019.
Hide Caption
45 of 48

Photos: Prince Philip: Decades in public life
Prince Philip leaves a London hospital in December 2019, after being admitted for observation and treatment in relation to a pre-existing condition.
Hide Caption
46 of 48

Photos: Prince Philip: Decades in public life
The Queen and Prince Philip pose for a photo in June 2020, ahead of Philip’s 99th birthday.
Hide Caption
47 of 48

Photos: Prince Philip: Decades in public life
The Queen and Prince Philip look at a homemade anniversary card that was given to them by their great-grandchildren Prince George, Princess Charlotte and Prince Louis in November 2020.
Hide Caption
48 of 48
















































Prince Philip stepped back from public life in 2017 and, due to his advancing age, has been taken to hospital several times in recent years.
In December 2019, he received hospital treatment for a pre-existing condition.
The Duke was born in Corfu, Greece, in 1921 and has English, Russian, German/Prussian and Danish ancestry. He and Queen Elizabeth married in November 20, 1947.
Prince Philip and Queen Elizabeth have both received at least one dose of a Covid-19 vaccine.
CNN’s Stephanie Halasz contributed to this story.