In 1366, the governments of Syria and Venice established a regular schedule for imported Levantine soda ash to arrive in Venice by cargo ship after those ships had delivered cotton to Syria. High-quality ash was a key input for high-quality glass. In the year 1395, 350 tons of ash were being imported. One hundred years later, 1750 tons arrived in Venice annually thus demonstrating the rise of the Venetian glass market throughout the 15th century.