 Complete the following phrase:  In the early 6th century, grape production in the Negev for the so-called vinum Gazentum Gaza wine in Latin experiences a major boom, due to the high demand for this product throughout Europe and the Middle East. This has been documented by studying ancient trash mounds at Shivta, Elusa and Nessana, which showed a sharp peak in the presence of grape pips and broken Gaza jars a type of amphorae used in this period to export Levantine goods from the port of Gaza, following a slower rise during the fourth and fifth centuries. However, mid-century two major calamities strike the Byzantine Empire and large parts of the world: a short period of climate change known as the Late Antique Little Ice Age 536-545, caused by huge volcanic eruptions in faraway places, which lead to 