The treaty established the forerunner of the European Community, now part of the European Union.
The exhibition of works from the Stone Age to the 20th century is at Rome's Palazzo Quirinale, the official residence of Italian President Giorgio Napolitano, who asked the 27 European Union heads of state to each lend a "masterpiece that is emblematic of their history," ANSA said Wednesday.
The exhibit includes masters such as William Turner, Titian, Diego Velasquez and Anton van Dyck. The earliest work is a Maltese Neolithic statue of a "Fat Lady," symbolizing motherhood and fertility, dating back to 3300-2500 BC.
Romania, Bulgaria and Cyprus contributed Byzantine works of art, while Italy and Germany lent paintings by Renaissance greats Titian and Albrecht Durer, respectively.
The most recent work is "Prophecy on Venice," a 1976 piece by Danish artist Per Kirkeby.
"These works show us how Europe has been, and is, singular and plural at the same time, capable of carving out a common cultural space and, as a result, a common project of economic, legal and political integration," Napolitano said.
The exhibit runs from Saturday through May 20.