Originally Posted By: tdtz
two events are listed in Bee's link

The wiki link Bee supplied lists the two historical events:

"... this tree is said to have been witness to the signing of the Magna Carta. It is also said to be the location where Henry VIII met Anne Boleyn in the 1530s."

Ann's beheading is a bit more "historic" than their meeting place, with the execution taking place in London Tower.