Monuments of antiquity might have become part of the history of their new homes. This doesn’t necessarily mean that this new history is now more important than their orriginal history however.
Courrier International 
Johan Schloemann on the restitution of works of art
Greece has repeatedly demanded that Great Britain return works of art. Johan Schloemann reflects on what would happen if all the looted works of art – some of which were taken in Antique times – had to be returned to their county of origin. “The monuments of antiquity that used to pass from country to country have become part of the history of their new homes. The same goes for the famous sculptures of the Parthenon temple at the Acropolis in Athens, which have been on show at the British Museum since 1916. This is an act of barbarism which would be illegal today, because nowadays each country has laws to protect its archaeological treasures. Still, this doesn’t mean you can turn back history like you turn back a clock. After all, this would mean all the other museums in which the art of humankind is now distributed would also have to be emptied.”
Süddeutsche Zeitung (Germany)