This is a large William Kent urn, circa 1735. Undoubtedly used in Alexander Pope's garden at Twickenham. Four of the original six urns are now in the formal gardens of Longleat House. One such urn forms the Shakespeare monument in Laskett Gardens. 
Handmade in Kent, England.

urn height (with lid) 59"
urn height (without lid) 41.5"
urn diameter 25"
pedestal height 39.5"
total height 98"

urn weight 340 lbs