He was shot with a bow and arrow, then tracked for two days before being finished off with a rifle. He was skinned, his head cut off as a trophy and his body dumped.
Now, the death of Africa's most famous lion, loved by tourists around the world, has sparked outrage and calls for a blanket ban on importing lion trophies into Europe.
Cecil, a 13-year-old male, was well-known for his size and distinctive black mane. He would often venture close to main roads in Zimbabwe's Hwange National Park, in the northwest corner of the country, providing tourists with plenty of photo opportunities and making him a social-media darling.
He was also part of an Oxford University research project and wore a GPS collar, allowing researchers to track his last movements.
A hunter reportedly paid park guides the equivalent of about $72,000 for a chance to kill the lion. The hunter used bait to lure Cecil out of the boundaries of the park, where hunting is illegal. He then shot Cecil silently with a bow and arrow in order to attract less attention and tracked the lion for 40 hours before shooting him with a rifle. The killing happened earlier this month, but only came to light recently. Cecil's head and skin have since been confiscated by the Zimbabwe Conservation Task Force.
Bryan Orford, who worked as a wildlife guide in Hwange National Park, told National Geographic that Cecil could bring in about $11,500 a day from tourists paying for tours, of which he was the main attraction, making him more valuable to the park alive than dead.
There were conflicting reports about the nationality of the hunter. Johnny Rodrigues, head of the Zimbabwe Conservation Task Force, told The Guardian the hunter was Spanish, while The Telegraph identified him as American. There were also reports of two other hunters who may have been involved in the killing.
The guide who accepted the hunter's bribe told The Telegraph neither he nor his client knew that the lion was Cecil.
"We did not know it was well-known lion. I had a licence for my client to shoot a lion with a bow and arrow in the area where it was shot," he told the paper.
Catherine Bearder, a member of the European Parliament, tabled a question with the European Commission calling for a ban on lion-trophy imports into the EU. Though lion trophies are currently only allowed in countries where it has been shown to be legal and sustainable, Zimbabwe is one of the few countries from which imports are still allowed.
The guide was a member of the Zimbabwe Professional Hunters and Guides Association, a Facebook post by the group confirmed. He has been suspended indefinitely, the group said.
"[The Association] will not tolerate any illegal hunting or any unethical practices by any of its members and their staff," the post stated.
Andrew J. Loveridge, a researcher at Oxford University who worked with tracked lions including Cecil, has written studies on lions that are lured out of protected parks and shot. The deaths of these animals can lead to other lions venturing closer to the edge of the park, in order to fill a "territorial vacuum" left by the killing. Those lions can in turn be more easily lured out of the parks.
Cecil is survived by six lionesses and about 24 cubs. The cubs might be in danger when a new male lion takes over the pack, as they sometimes kill cubs to encourage female lions to mate with them.