This week, the Dublin Zoo said goodbye to one of its most beloved and famous residents: Betty, the chimpanzee who was their longest resident and oldest living chimp in human care, has died at 62.

According to a blog post from the zoo, Betty suffered from age-related conditions that were harming her quality of life, and the difficult decision was made to euthanize her to avoid future discomfort.

While it’s sad she is gone, Betty lived a long life, surpassing the life expectancy of a chimp in captivity, and the zoo says she was the oldest living chimp in human care at the time of her passing.

She was remembered by Dublin Zoo team leader Helen Clarke Bennett, who has been a zookeeper since 1987 and has known Betty for decades.

Betty, a West African chimpanzee, arrived in Dublin in 1964. Bennett writes that at the time the Dublin Zoo still followed the “style of the early Victorian era zoos,” and Betty took part in bygone stunts like “Chimp Tea Parties.”

Over her decades in captivity, Betty witnessed significant changes and improvements to zoo standards: in the ’90s, the chimp habitat was upgraded from a concrete “pit” with metal bars to an island habitat with trees.

Bennett wrote that she had known Betty since her early days at the zoo, as her father Michael Clarke cared for her at the time. He described the chimp as “always strong-minded” and persistent in getting what she wanted.

For most of her life, Betty was inseparable from her best friend Wendy, who arrived in 1964. The two chimps made for one of the zoo’s most endearing duos.

“While Wendy had a cheeky side, Betty was well able to keep her honest!” Bennett wrote. “One of my favorite images will always be that of Betty putting her arm around Wendy to encourage her to go outside with the rest of the troop when Wendy was stubbornly refusing to leave while the habitat was cleaned.”

In 2012, the zoo held a joint 50th birthday party for Betty and Wendy. Wendy passed away in 2014, and zoo staff thought that the broken-hearted Betty wouldn’t be far behind.

And yet, she continued to survive for another decade, holding the position of dominant female among the zoo’s chimps and becoming the zoo’s longest-standing resident.

Bennett wrote that in Betty’s later years, she was under constant wellness supervision, and she began suffering from chronic arthritis and declining kidney function, which impacted her mobility and weight.

When all medical and surgical options were exhausted, they made the difficult but human decision to euthanize the beloved chimp. While she may be gone, Betty will always be remembered as a one-of-a-kind original and a favorite of generations of zoogoers.

“While I’m incredibly sad to say goodbye to a companion I’ve had since childhood, I’m confident that euthanising Betty was the correct decision, ensuring she didn’t suffer unnecessarily and allowing her to keep her dignity to the very end. I take huge comfort in that,” Bennett wrote.

“There will never be another like Betty, and she will be missed dearly by everyone here in Dublin Zoo as well as the many generations of visitors who were fortunate to know her.”

Rest in peace, Betty. What a remarkably long life you lived, and it’s clear you were loved by your caretakers and visitors.