The poet Petrarch arranged to leave his personal library to the city of Venice, but it never arrived. The Venetian tradition that this was the founding of the Biblioteca Marciana is an anachronism; it was founded a century later.
When Petrarch broke up his personal collections at Parma and Vaucluse he had formed the habit of traveling with large bales of manuscripts in a long cavalcade. In his middle age he became tired of carrying his large collection of manuscripts and books around in his extensive travels. He came to the conclusion that he would offer his collection of manuscripts to the Republic of Venice, on condition that it should be properly housed, and should never be sold or divided. This was in exchange for a permanent residence that he and his daughter's family could live in. He decided he wanted to have his valuable collection of manuscripts and ancient books put into a public library on the concept of those of classical antiquity, like Ptolemy II Philadelphus, who built the Library of Alexandria. He called on his Venetian friend Grand Chancellor Benintendi de Ravagnani on this matter. Benintendi enthusiastically took on the idea of receiving Petrarch's books and manuscripts. He immediately prepared the Deliberation for the Great Council meeting in the beginning of September 1362 on this issue. It gave its approval for the donation of Petrarch's books to the church of Saint Mark (Marciana) as the protector of this precious gift, being the symbol of Venice.
The agreement between Petrarch and the Republic of Venice was that none of the ancient books nor Petrarch's manuscripts were to be dispersed. They were to be preserved in a safe place in memory and honor of the great poet. In return for this Petrarch was to have the use of a worthy residence at public expense during his lifetime. Petrarch received the Palazzo Molina, known locally as Casa Molin delle due Torri. The memorandum agreement stipulated that Petrarch could keep his library until his death and did not say he had to live in Venice. Petrarch and his daughter Francesca with his son-in-law Francescuolo da Brossano moved there in 1362. It became their prime residence from 1362–1367 along with his personal library of books and manuscripts.