xpanded its territory into the peninsula in the late Middle Ages, while Florence developed into a highly organized commercial and financial city-state, becoming for many centuries the European capital of silk, wool, banking and jewelry.
In the south, Byzantine Sicily had become an Islamic emirate in the 9th century, thriving until the Italo-Normans conquered it in the late 11th century together with most of the Lombard and Byzantine states of southern Italy. Through a complex series of events, southern Italy developed as a unified kingdom, first under the House of Hohenstaufen, then under the Capetian House of Anjou and, from the 15th century, the house of Aragon (although Sicily was a separate Aragonese kingdom from the late 13th to the 15th century). In Sardinia, the former Byzantine provinces became independent states known as giudicati, although most of the island was under Genoese or Pisan control until the Aragonese conquered it in the 15th century.
The Black Death pandemic in 1348 left its mark on Italy by killing one third of the population. However, the recovery from the disaster of the Black Death led to a resurgence of cities, trade and economy which greatly stimulated the successive phases of Humanism and Renaissance, cultural movements both born in the peninsula, and later spread in Europe.
In the 14th and 15th centuries, Northern and upper Central Italy were divided into a number of warring city-states, the rest of the peninsula being occupied by the larger Papal States and Naples. The strongest among these city-states annexed the surrounding territories giving birth to the Signorie, regional states led by merchant families which founded local dynasties. Dominated by merchant oligarchies, they enjoyed a relative freedom and nurtured academic and artistic advancement. Warfare between the states was common, invasion from outside Italy confined to intermittent sorties of Holy Roman Emperors. These wars were