The "single most important" object ever donated to the national collection has gone on display.
The Byzantine sardonyx bowl has been gifted to the National Museums Scotland from the estate of Edmund de Rothschild, who died in 2009.
Under the Acceptance in Lieu scheme, donors are allowed to leave major works of art to the nation instead of paying inheritance tax.
The Hamilton-Rothschild tazza is a bowl mounted on a 16th-century gold stand. The bowl was bought by the 10th Duke of Hamilton while he was the British ambassador in Russia from 1807 to 1808. He then purchased the enamelled gold foot in 1812 and united the two pieces to create the tazza.
It was one of six items from the Hamilton Palace collection which was sold to Alfred de Rothschild in 1882 shortly before the collection was sold at auction.
Sir Angus Grossart, chairman of National Museums Scotland said: "The Hamilton-Rothschild tazza is the single most important acquisition that National Museums Scotland has made in many decades. Acquiring this wonderful work of art demonstrates our enhanced international ambitions for our collections and underlines our aspirations. We have a strategic vision for our future potential and are committed to build upon major acquisitions."
Dr Gordon Rintoul, director of National Museums Scotland, said: "We are delighted to have acquired this remarkable object for the national collections. It greatly enhances our already significant international collections of European art and design."
The tazza went on display on Tuesday in the National Museum of Scotland.
