He also introduced the sequence of Fibonacci numbers, which he used as an example in Liber Abaci. As of the beginning of 2020 according to our estimates Italy had the following population age distribution: We prepared a simplified model of the population distribution pyramid which is broken down into 3 main age groups. [180] The descendants of these Albanian emigrants, many still retaining the Albanian language, the Arbëresh dialect, have survived throughout southern Italy, numbering about 260,000 people,[181] with roughly 80,000 to 100,000 speaking the Albanian language.[182][183]. [175][176] Beside that, minor but significant settlements of Slavs (the so-called Schiavoni) and Arbereshe in Italy have been recorded. Louis divided the empire among his sons, and Frankish Italy became part of Middle Francia, extending as far south as Rome and Spoleto. His achievements include the invention of the thermometer and key improvements to the telescope and consequent astronomical observations, and ultimately the triumph of Copernicanism over the Ptolemaic model. Islamization of Shqeptaret: The clas of Religions in Medieval Albania. [122] According to Strabo they were not Celts, but later became influenced by the Celtic culture of their neighbours, and thus are sometimes referred to as Celticized Ligurians or Celto-Ligurians. Italians have influenced and contributed to fields like arts and music, science, technology, fashion, cinema, cuisine, sports, jurisprudence, banking and business. The popes finally defeated the Lombards with the aid of two Frankish kings, Pepin the Short and Charlemagne. [105][106] This includes pre-Indo-European language people, such as the Etruscans, Rhaetians, Camuni and the Ligures,[107] and pre-Roman Indo-European language peoples, like the Celts (Gauls) in northern Italy, the Italic peoples throughout the peninsula (such as the Latino-Faliscans, the Osco-Umbrians, the Sicels and the Veneti), and a significant number of Greeks in southern Italy and Sicily (Magna Graecia). In this capacity, they provided great impetus to the developing Renaissance, began in Florence in the 14th century,[82] and led to an unparalleled flourishing of the arts, literature, music, and science. [190] Alternatively, rural and agro-intensive Southern Italy was seen as economically backward and was mainly populated by lower class peasantry. [165][166][167], An estimated 20,000 Swabians and 40,000 Normans settled in the southern half of Italy during this period. Later, Italy was at the forefront of the progressive rock movement of the 1970s, with bands like PFM and Goblin. Italy - Italy - Demographic trends: Throughout the centuries, Italy’s population curve has undergone many changes, often in parallel development with population trends in other European countries.