The best hypothesis is that Murano origins is analogous to that of the many sites founded by refugees of Altino during the barbarian invasions. Is however only in 840 that the first traces appear, when in Pactum Lotharii the name Amorianas is cited. The documents of the centuries XI and XII describe it as transit locations for the migratory flow from Torcello and Equilio (Jesolo) and directed to Venice. The city has always been inserted in Venice Marittima, hit had a certain degree of autonomy until 1171, when it was united to Santa Croce. From 1275 it was instead governed by its own mayor and the Great Council made up of a number of nobles of Murano who could enact laws and coin its own currency (the Osella). Soon, Murano became the center for glass art work, thanks to a decree of the Serenissima Republic, which in 1295 sanctioned the transfer of the furnaces from Venice: because of the frequent fires that they were causing..