Hohenstaufen in the context of "Frederick II, Holy Roman Emperor"

Italy has been inhabited by humans since the Paleolithic. During antiquity, there were many peoples in the Italian peninsula, including Etruscans, Latins, Samnites, Umbri, Cisalpine Gauls, Greeks in Magna Graecia and others. Most significantly, Italy was the cradle of the Roman civilization. Rome was founded as a kingdom in 753 BC and became a republic in 509 BC. The Roman Republic then unified Italy forming a confederation of the Italic peoples and rose to dominate Western Europe, Northern Africa, and the Near East. The Roman Empire, established in 27 BC, ruled the Mediterranean region for centuries, contributing to the development of Western culture, philosophy, science and art.

During the early Middle Ages, Italy experienced the succession in power of Ostrogoths, Byzantines, Longobards and the Holy Roman Empire and fragmented into numerous city-states and regional polities, a situation that would remain until the unification of the country. These polities and the maritime republics, in particular Venice and Genoa, rose to prosperity. Eventually, the Italian Renaissance emerged and spread to the rest of Europe, bringing a renewed interest in humanism, science, exploration, and art with the start of the modern era. In the medieval and early modern era, Southern Italy was ruled by the Norman, Swabian and Angevin dynasties and the Aragonese, French and Spanish crowns. Central Italy was largely part of the Papal States.

An Imperial Estate (Latin: Status Imperii; German: Reichsstand, plural: Reichsstände) was an entity or an individual of the Holy Roman Empire with representation and the right to vote in the Imperial Diet (Reichstag). Rulers of these Estates were able to exercise significant rights and privileges and were "immediate", meaning the only authority above them was that of the Holy Roman Emperor. They were thus able to rule their territories with a considerable degree of autonomy.

The system of imperial states replaced the more regular division of Germany into stem duchies in the early medieval period. The old Carolingian stem duchies were retained as the major divisions of Germany under the Salian dynasty, but they became increasingly obsolete during the early high medieval period under the Hohenstaufen, and they were finally abolished in 1180 by Frederick Barbarossa in favour of more numerous territorial divisions. From 1489, the Imperial Estates represented in the Diet were divided into three chambers, the college of prince-electors (Kurfürstenkollegium/den Kurfürstenrat), the college of imperial princes (Reichsfürstenrat) and the college of imperial cities. Counts and nobles were not directly represented in the Diet in spite of their immediate status, but were grouped into "benches" (Grafenbänke) with a single vote each.Imperial Knights and imperial villages had immediate status but were not represented in the Diet.

The history of Sicily has been influenced by numerous ethnic groups. It has seen Sicily controlled by powers, including Carthaginian, Greek, Roman, Vandal and Ostrogoth, Byzantine, Arab, Norman, Aragonese, Spanish, Austrians, but also experiencing important periods of independence, as under the indigenous Sicanians, Elymians, Sicels, the Greek-Siceliotes (in particular Syracuse with its sovereigns), and later as County of Sicily, and Kingdom of Sicily. The Kingdom was founded in 1130 by Roger II, belonging to the Siculo-Norman family of Hauteville. During this period, Sicily was prosperous and politically powerful, becoming one of the wealthiest states in all of Europe. As a result of the dynastic succession, the Kingdom passed into the hands of the Hohenstaufen. At the end of the 13th century, with the War of the Sicilian Vespers between the crowns of Anjou and Aragon, the island passed to the latter. In the following centuries the Kingdom entered into the personal union with the Spaniard and Bourbon crowns, while preserving effective independence until 1816. Sicily was merged with the Kingdom of Italy in 1861.Although today an Autonomous Region, with special statute, of the Republic of Italy, it has its own distinct culture.

Sicily is both the largest region of the modern state of Italy and the largest island in the Mediterranean Sea. Its central location and natural resources ensured that it has been considered a crucial strategic location due in large part to its importance for Mediterranean trade routes. Cicero and al-Idrisi described respectively Syracuse and Palermo as the greatest and most beautiful cities of the Hellenic World and of the Middle Ages.

Frederick Barbarossa (December 1122 – 10 June 1190), also known as Frederick I (German: Friedrich I; Italian: Federico I), was the Holy Roman Emperor from 1155 until his death in 1190. He was elected King of Germany in Frankfurt on 4 March 1152 and crowned in Aachen on 9 March 1152. He was crowned King of Italy on 24 April 1155 in Pavia and emperor by Pope Adrian IV on 18 June 1155 in Rome. Two years later, the term sacrum ("holy") first appeared in a document in connection with his empire. He was later formally crowned King of Burgundy, at Arles on 30 June 1178. His nickname of Barbarossa (meaning "Red Beard" in Italian) "was first used by the Florentines only in 1298 to differentiate the emperor from his grandson, Frederick II ... and was never employed in medieval Germany" (the colour red was "also associated in the Middle Ages with malice and a hot temper"; in reality, Frederick's hair was "blond", although his beard was described by a contemporary as "reddish"). In German, he was known as Kaiser Rotbart, which in English means "Emperor Redbeard". The prevalence of the Italian nickname, even in later German usage, reflects the centrality of the Italian campaigns under his reign, and "remains to this day one of the [most] powerful historical monikers."

Frederick was by inheritance Duke of Swabia (1147–1152, as Frederick III) before his imperial election in 1152. He was the son of Duke Frederick II of the Hohenstaufen dynasty and Judith, daughter of Henry IX, Duke of Bavaria, from the rival House of Welf. Frederick, therefore, descended from the two leading families in Germany, making him an acceptable choice for the Empire's prince-electors. Frederick joined the Third Crusade and opted to travel overland to the Holy Land. In 1190, Frederick drowned attempting to cross the Saleph River, leading to most of his army abandoning the Crusade before reaching Acre.

The Duchy of Bavaria (German: Herzogtum Bayern) was a frontier region in the southeastern part of the Merovingian kingdom from the sixth through the eighth century. It was settled by Bavarian tribes and ruled by dukes (duces) under Frankish overlordship. A new duchy was created from this area during the decline of the Carolingian Empire in the late ninth century. It became one of the stem duchies of the East Frankish realm, which evolved as the Kingdom of Germany and the Holy Roman Empire.

During internal struggles in the Ottonian dynasty, the Bavarian territory was considerably diminished by the separation of the newly established Duchy of Carinthia in 976. Between 1070 and 1180, the Holy Roman Emperors were again strongly opposed by Bavaria, especially by the ducal House of Welf. In the final conflict between the Welf and Hohenstaufen dynasties, Duke Henry the Lion was banned and deprived of his Bavarian and Saxon fiefs by Emperor Frederick Barbarossa. Frederick passed Bavaria over to the House of Wittelsbach, which held it until 1918. The Bavarian dukes were raised to prince-electors during the Thirty Years' War in 1623, and to kings by Napoleon in 1806. The duchy chaired the bench of the secular princes to the Reichstag of the Empire.

A stem duchy (German: Stammesherzogtum, from Stamm, meaning "tribe", in reference to the Franks, Saxons, Bavarians and Swabians) was a constituent duchy of the Kingdom of Germany at the time of the extinction of the Carolingian dynasty (death of Louis the Child in 911) and through the transitional period leading to the formation of the Ottonian dynasty. The Carolingians had dissolved the original tribal duchies of the Empire in the 8th century. As the Carolingian Empire declined, the old tribal areas assumed new identities. The five stem duchies (sometimes also called "younger stem duchies" in contrast to the pre-Carolingian tribal duchies) wereBavaria, Franconia, Lotharingia (Lorraine), Saxony and Swabia (Alemannia). The Salian emperors (reigned 1027–1125) retained the stem duchies as the major divisions of Germany, but the stem duchies became increasingly obsolete during the early high-medieval period under the Hohenstaufen, and Frederick Barbarossa finally abolished them in 1180 in favour of more numerous territorial duchies.

The term Stammesherzogtum as used in German historiography dates to the mid-19th century, and from the beginning was closely related to the question of national unification. The term's applicability, and the nature of the stem duchies in medieval Germany, consequently have a long history of controversy.The overly literal or etymologizing English translation "stem duchy" was coined in the early 20th century. While later authors tend to clarify the term by using the alternative translation "tribal", use of the term "stem duchies" has become conventional.