A TREE BIG ENOUGH TO HOLD A BANQUET INSIDE IT. Thomas Pakenham reviewed THE LONG, LONG LIFE OF TREES by Fiona Stafford in The New York Review of Books (December 8). It is hard to know how long an oak tree can live because they are hollowed out as they get older so most of the tree rings disappear. Pakenham discusses several ancient oaks which are estimated to be hundreds of years old. He singles out the Bowthorpe Oak in Lincolnshire, which he guesses is at least 700 years old. Pakenham says that in the 18th century diner parties for up to 17 people were given inside the tree.
This wikipedia entry estimates that the Bowthorpe Oak is about 1000 years old and has a girth (apparently the diameter) of over 40 feet. The entry has photos of the Bowthorpe Oak, which is pollarded.