The ancient city of Rome was huge by any standards - approaching one million inhabitants by the late first century BC. Coins were in constant use and the demand for them was high. But the mint was severely limited in its output by the technology available - that of striking coins by hand. While modern mechanised mints can produce billions of coins a year, ancient mints struck each coin with the blow of a hammer, making production relatively slow and laborious.Because of this, the mints were often unable to produce enough low-value bronze coins, which were needed in larger quantities than the more valuable silver or gold coins. To speed up the process, coin blanks were sometimes cast in strips, like this rare example, and then struck in quick succession, before being separated into individual coins. This was an ancient attempt at mass-production to supply one of the world's first urbanised consumer societies with money. These bronze coins, known as asses, were made in the name of the Roman Republican moneyer Lucius Calpurnius Piso Frugi.