On loan and on display at the British Museum since 1963, the cup has been bought jointly by the museum and Wiltshire Heritage Museum in Devizes.
The chalice was donated to St Cyriac's Church in Lacock more than 400 years ago and has now been sold to help pay for maintenance work at the church, 'BBC News' reported.
"I am delighted that this beautiful and rare cup has been acquired so that it can continue to be enjoyed by visitors to the British Museum as well as in the Wiltshire Museum," said Neil MacGregor, from the British Museum.
Used for feasting in the medieval period, a spokeswoman for the British Museum said it was a "rare survivor with a unique history".