Cremation of the dead was a common practice in the Roman Empire. Out of respect for the body and anticipation of the resurrection of the body Christians did not cremate their dead, but buried them. This particular urn was made before Christianity became state religion in the Roman Empire. It was made for a child from a wealthy family as the artistry and material indicate.
This 2005 conservation was courtesy of The Minnesota/North Dakota Chapter of the Patrons of the Arts in the Vatican Museums.