No one knows exactly when or where glass was first made. Glass appears to have been produced as far back as the second millennium BC by the Egyptian or perhaps the Phoenician.
According to the ancient Roman historian Pliny(AD 23-79), Phonecian merchants tranporting stones discovered glass in the region of Syria around 5000 BC. Pliny tells how the merchants, after landing, rested cooking pots on blocks of nitrate placed by their fire. With the intense heat of the fire, the blocks eventually melted and mixed with the sand of the beach to form an opaque liquid.
Glass was less common back then than it is today, a thing that made it precious. And in the Bible glass has been compared to gold(Job 28:17).

The end of the 1st cnetury BC, blowing through a hollow tube was probably discovered along the Eastern Mediterranean coast, probably in Syria, where the experienced glass blower can quickly  produce an intricate and symmetrical shape out of the "gather" of molten glass at the end of his tube(rod). A visit to a glass blowing studio in Syria, you would get the feeling that little has changed in the techniques used since then.
The glassblowing innovtion, along with the powerful backing of the Roman Empire made glass products more accessible to the common people. As the size of the Roman Empire increased, the art of glass making spread to many countries.

A flourishing glass industry did not develop in Europe until the 13th century, when Venice became a major glassmaking centre. They may have picked up their glass making techniques through their contacts with the near East countries during the Crusades. The Venitians provided a link between the ancient and modern glass making art. Venetian glass is renowned for it's brilliance, light and imaginative forms.