Chester Zoo said it was “deeply saddened” by the death of a lion which lived to the “remarkable” age of 18.
Asiatic lion Iblis, known for its “deep, booming call”, had “far exceeded” the usual life expectancy of wild lions, according to zoo staff.
Mark Brayshaw, head of mammals at Chester, said Iblis had “captured the heart of millions with his regal, majestic presence” during his 15 years at the zoo.
Asiatic lions are one of the world’s rarest big cat species with less than 900 estimated to be still living in the wild.
Once spanning northern Africa, Greece, Turkey and Asia, they all now live in a single forest in India, leaving the species vulnerable to the threat of disease, habitat loss and natural disasters.
Chester Zoo said as a national conservation zoo it would “continue to play a vital role in efforts to safeguard Asiatic lions”.
Mr Brayshaw said: “His long and full life is a true reflection not only of the incredible care and love shown to him by our dedicated Carnivore Team, but also of the enriched environment they created for him.
“Iblis was not only well cared for, he was held in great affection.
“He spent his years thriving, enjoying his surroundings and leaving a lasting impression on everyone who knew him.
“His absence will be especially felt by those who shared in his wonderful journey.”
Mr Brayshaw added Chester would welcome two “carefully matched” new Asiatic lions in the coming months.