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Economy

The high fertility of the land led the Norman kings to bring settlers from neighbouring regions or to resettle farmers to areas where cultivation of land was needed. This led to an increase in agricultural production. The main sources of wealth for the Kingdom of Sicily in that time were its maritime cities, most important of which were the ancient port cities of Naples and its nearby counterpart Amalfi, from which local products were exported. The main export was durum wheat, with other exports including nuts, timber, oil, bacon, cheese, furs, hides, hemp and cloth. Grain and other dry products were measured in salme, which was equivalent to 275.08 litres in the western part of the Kingdom, and 300.3 litres in the eastern part. The salma was divided in 16 tumoli. One tumolo was equivalent to 17,193 litres. Weight was measured in cantari. One cantaro was equivalent to 79.35 kilograms (174.9 lb) and was divided in one hundred rottoli. Cloth was measured in canne. One canna was 2.06 meters long. By the end of the 12th century, Messina had become one of the leading commercial cities of the kingdom.

Under the kingdom, Sicily's products went to many different lands. Among these were Genoa, Pisa, the Byzantine Empire, and Egypt. Over the course of the 12th century, Sicily became an important source of raw materials for north Italian cities such as Genoa. As the centuries went on, however, this economic relationship became less advantageous to Sicily, and some modern scholars see the relationship as definitely exploitative. Furthermore, many scholars believe that Sicily went into decline in the Late Middle Ages, though they do not agree about when this decline occurred. Clifford Backman argues that it is a mistake to see the economic history of Sicily in terms of victimization, and contends that the decline really began in the second part of the reign of Frederick III, in contrast to earlier scholars who believed that Sicilian decline had set in earlier. Where earlier scholars saw late medieval Sicily in continuous decline, Stephen Epstein argued that Sicilian society experienced something of a revival in the 15th century.

Various treaties with Genoa secured and strengthened the commercial power of Sicily.

The feudalisation of society during the Angevin rule reduced royal wealth and treasury. The dependence of the Angevins on north Italian commerce and financing by Florentine bankers were the main factors which led to the decline of the Kingdom's economy. The continuation of the economic decline combined with the increased population and urbanization led to decrease of agrarian production.

In 1800, one-third of the available crops was cultivated with obsolete methods, exacerbating the problem. In the later period of Spanish rule, the trading system was also inefficient compared with previous periods because of high taxes on exports and monopolising corporations which had total control of prices.