The treasure belonging to the Basilica of S.Marco is made up of 283 pieces of gold, silver, glass and other materials; the first part of it dates back to the 13th century, when Constantinople was plundered by the Venetian army during the fourth crusade (between 1204 and 1261). The most unusual and precious masterpiece from this pillage is inside the Basilica, on the main altar: the so called Pala d’oro (i.e. golden altar piece) which preserves the Saint’s relics. It’s a gold-plated silver frame with 255 Byzantine enamels and over 200 emeralds, rubies, amethysts, pearls and other precious stones created between the 13th and the 14th century.