Byzantine, 10th-12th century. 4 1/8” diameter. Gray terracotta, of squat turnip form. The shoulder impressed with a repeated sword motif. Bee hive form spout for the wick. A little deformed and with surface cracks as made, neither of which affects its function. These were used in the Crusades, at sea and in siege situations. Known as "Greek fire" these were filled with flammable pitch and thrown or catapulted. Upon impact, they would burst spewing their burning contents which would start fires as well as burn any enemy in their path. In the absence of antibiotics, such burns usually led to a slow death from infection. Constantinople is situated on the Bosporus Strait and Sea of Marmara with a wall against the water. It was both attacked and defended variously by sea. These were instrumental in both situations and played an important role in the Sack of Constantinople in 1204 which marked the conclusion of the fourth Crusade.