Vessels were made with a core that was usually made from clay. Hot glass was put on the core in a wrapping motion. They core was removed after the glass was cool and they would have their vessel. At this time, only a handful of people knew how to work with glass and it was only owned by the elite.
Glass blowing was discovered around 50 BC in the Roman Empire. This discovery made it possible to make glass in any shape. Glass objects became available to more people and more extravagant pieces were being created. It was at this time that glassblowers started putting inlays in the glass.
In the Dark Ages, glass making came almost to a standstill. The Catholic Church started gaining power in the 12th century and Dark Ages started to end. Glassblowers started to appear in Venice. Around 1200 AD, the Venetian glassmakers had their first guild. All the glassblowers in Venice had to move to an island called Murano in 1291. This was to avoid fires from their furnaces in Venice and to control the industry. If a glassblower tried to leave the island, his punishment was death. Some did escape and eventually introduced their art to Europe.
Glassblowing was brought to America in 1607 by the settlers in Jamestown. The majority was used for windows and bottles.
Glass making evolved and improved over the years. Glassblowing is now considered an art form and the blowers are now considered artists. They still blow the glass in the same the way glassblowers did a few thousand years ago.