Prince Philip has been admitted to hospital for hip surgery, Buckingham Palace announced on Tuesday.
In a statement, the palace said: "His Royal Highness The Duke of Edinburgh was admitted to King Edward VII Hospital in London this afternoon, for planned surgery on his hip which will take place tomorrow."
The Duke of Edinburgh, 96, missed Easter services alongside Queen Elizabeth at Windsor Castle over the weekend due to the issue.
However, Prince William and Duchess Catherine - who are expecting their third little prince or princess any day now - made a surprise appearance at the event alongside the Queen.
Other royals who made up the congregation included Zara Tindall, who is expecting her second child with husband Mike Tindall, and the Queen's granddaughters Princesses Beatrice and Eugenie.
Last week, Prince Philip made the decision not to attend the traditional Maundy church service.
He had been listed in the Order of Service as attending but pulled out at the last minute.
At the time, Buckingham Palace would not comment on the royal's health. However, a palace spokesperson did note: "The Order of Service was printed some weeks ago when it was hoped the Duke would be able to take part. HRH has since decided not to attend."
Nonetheless, the Queen appeared in good spirits as she attended the service at St George's Chapel, Windsor Castle – the same church Prince Harry and Meghan Markle have chosen for their wedding on 19 May.
The service commemorates the Last Supper of Jesus Christ and, as is tradition, presents an opportunity for the monarch to show humility as she distributes gifts to pensioners. This year, Her Majesty was pictured smiling warmly as she distributed 'Maundy money' to 92 men and 92 women - marking the fact that she will soon turn 92.
In August last year, Philip officially retired from public life after decades of loyal service.
He is considered one of the hardest-working royals of all time and conducted 110 days of appearances last year, outnumbering several young family members - including Prince William.
We wish the well-loved royal a speedy recovery!