After the fall of the Western Roman Empire in the early centuries AD, the old Mediterranean economy collapsed and the volume of trade went down drastically. Its eastern successor, the Byzantine Empire, neglected to revive overland trade routes but was dependent on keeping the sea lanes open to keep the empire together. Bulk trade fell around 600-750 while the luxury trade increased. Galleys remained in service, but were profitable mainly in the luxury trade, which set off their high maintenance cost. [79] In the 10th century, there was a sharp increase in piracy which resulted in larger ships with more numerous crews. These were mostly built by the growing city-states of Italy which were emerging as the dominant sea powers, including Venice, Genoa and Pisa. Inheriting the Byzantine ship designs, the new merchant galleys were similar dromons, but without any heavy weapons and both faster and wider. They could be manned by crews of up to 1,000 men and were employed in both trade and warfare. A further boost to the development of the large merchant galleys was the upswing in Western European pilgrims traveling to the Holy Land [80] [links]