Portland_Vase The Portland Vase is a first century BC Roman cameo glass vase, which served as an inspiration to many glass and porcelain makers from about the beginning of the 18th century onwards. Since 1945 the vase has belonged to the British Museum in London (reference - GR 1945,0927.1) ; on display in Room 70, RomeThe vase is about 25 centimetres high and 56 in circumference. It is made of violet-blue glass, and surrounded with a single continuous white glass cameo depicting seven figures (humans and gods).