At the same period the feudalisation of the Kingdom of Sicily was intensified , through the enforcement of feudal bonds and relations among its subjects . In 1669 the eruption of Mount Etna destroyed Catania . In 1693 , 5 % of the Kingdom 's population was killed because of earthquakes . In that period there were also plague outbreaks . The 17th and 18th century were an era of decline of the Kingdom . Corruption was prevalent among the upper and middle classes of the society . Widespread corruption and maltreatment of the lower classes by the feudal lords led to the creation of groups of brigands , attacking the nobility and destroying their fiefs . These groups which were self-named " Mafia " , were the foundation of the modern Sicilian Mafia . The escalation of revolts against the monarchy eventually led to the unification with Italy
earthquakes
1693 Sicily earthquake
Kingdom of Sicily