The Tower of London's Queen Raven, Merlina, is missing and feared dead, according to staff at the historic site.
Known by her keeper as the "undisputed ruler of the roost" Merlina hasn't been seen at the Tower for several weeks.
Merlina's disappearance means there are now seven ravens here at the Tower just one more than the required six.
Legend states at least six ravens must be kept at the 11th Century fortress or the kingdom of Britain will fall.
Staff say she will be "greatly missed" and there are no immediate plans to fill Merlina’s vacancy.
"In time we hope that a new chick from our breeding programme will be up to the formidable challenge of continuing her legacy," a statement from the Tower of London said.
"Though it isn’t unusual for our ravens to roam outside the walls, free-spirited Merlina has previously always returned to the Tower and to the Ravenmaster and his team, with whom she shared a wonderfully close bond," it added.
Charles II is thought to have been the first to insist that the ravens of the Tower be protected after he was warned that the crown and the Tower itself would fall if they left.