The National Library of St Mark's (The Biblioteca Nazionale Marciana or Biblioteca di San Marco) is a library located at the Piazzetta in Venice, Italy. It is one of the earliest surviving public manuscript depositories in the country, holding one of the greatest classical texts collections in the world. The library is named after St. Mark, the patron saint of Venice.
The library was provided with a Renaissance building designed by Jacopo Sansovino. The first sixteen arcaded bays of his design were constructed during 1537 to 1553, with work on frescoes and other decorations continuing until 1560. Sansovino died in 1570, but in 1588, Vincenzo Scamozzi undertook the construction of the additional five bays, still to Sansovino's design, which brought the building down to the molo or embankment, next to Sansovino's building for the Venetian mint, the Zecca.
Today, besides about a million printed books, the Biblioteca Marciana contains about 13,000 manuscripts and 2883 incunabula and 24,055 works printed between 1500 and 1600. There are many illuminated manuscripts. Among the irreplaceable treasures are unique scores of operas by Francesco Cavalli and sonatas by Domenico Scarlatti.