A giant, ancient oak tree located in the the Sherwood Forest — the iconic setting of the “Robin Hood” legend — has died, one of the U.K.’s top bird and wildlife conservation charities said. 

Famous for its enormous trunk — about 36 feet in circumference — and gnarled branches, the Major Oak was believed to be about 1,200 years old, according to the RSPB Bird & Wildlife Conservation Charity.

The tree had been in “visible decline” for several years, the charity said and failed to produce any leaves this spring. 

 “Whilst the tree’s failure to produce leaves this year is heart-breaking for everyone — from the many people over the years who have looked after this magnificent tree to the millions who have travelled here to see it — we know the Major Oak will have a lasting legacy, first and foremost because it is so inextricably linked to Robin Hood and Sherwood Forest,” Hollie Drake, senior site manager at RSPB Sherwood Forest, said in a statement. 

The organization said it couldn’t determine the exact cause of the tree’s demise. 

 Among the factors cited were poor soil and a weakened root system as well as “well-intentioned efforts to preserve the tree’s impressive shape” over the years, including metal bracing and coverings that prevented the tree from aging naturally, the organization said. 

The group also cited the effects of climate change and recent heat waves and drought. 

While the tree has died, the organization said the oak will remain standing in its place in the park, “continuing as an emblem in the landscape and providing valuable decaying wood habitat.”

In addition, acorns and cuttings from the tree have already been grown into saplings.

“There are Major Oak saplings planted in locations right around the world, so we are planning work to ensure that its offspring will grow and generate their own acorns — and legends — for centuries to come,” the organization said.