The Tower of London's "queen" raven is missing and feared dead, according to staff at the fortress.
Merlina, who joined the flock in 2007, has not been seen for several weeks.
The Tower usually has six ravens at any time and, according to legend, if they ever leave then both the fortress and the kingdom will fall. There are currently seven in residence.
A spokesman said Merlina's "continued absence indicates to us that she may have sadly passed away".
He added: "Merlina was our undisputed ruler of the roost, queen of the Tower ravens.
"She will be greatly missed by her fellow ravens, the ravenmaster, and all of us in the Tower community."
Ravenmaster Christopher Skaife said he would be taking some time to mourn Merlina, according to the Local Democracy Reporting Service.
"I know so many of you lovely folk will be saddened by this news," he said in a social media statement.
"None more than me. Please excuse my absence for a few days."
Tower staff added that they had no immediate plans to replace Merlina.
Charles II is believed to have been the first monarch to officially decree that the birds must be kept at the Tower at all times.
When numbers fell to just a single raven guard, Winston Churchill ordered that the flock — known as an "unkindness" — was increased to at least six.
In 2018 the Tower launched a raven breeding programme after Historic Royal Palaces warned it was becoming "increasingly difficult" to source the birds.