A certain stability, or at least consistency, returned to Italy in the middle of the tenth century when Otto, the Saxon King of Germany, claimed the throne of Italy through his wife Adelaide (the daughter, widow and jilter of three previous kings of Italy) and made himself King of the Lombards. Following Charlemagne’s example, he travelled to Rome in 962 and had the pope crown him emperor, thus inaugurating three centuries of rule over Italy by three dynasties of German emperors – Saxon, Salian and Swabian (usually known as Hohenstaufen) – with brief interludes supplied by members of the Welf and Supplinburger families. The gallery consisted of one Lothair, two Fredericks, three Conrads, four Ottos and seven Henrys.

The rulers styled themselves rex romanorum et semper augustus (‘king of the Romans and ever emperor’), and the coronations that their realms required indicate both the complexity of their roles and the difficulty in fulfilling separate duties as kings of Germany, kings of Italy and Holy Roman emperors. After being elected by the German princes, they were crowned kings of Germany at Charlemagne’s beloved Aachen (Aix-la-Chapelle) and became then also known as kings of the Romans. Later they crossed the Alps to receive the iron crown of the Lombards at Pavia, Monza or Milan. The last stage of the process was the journey to Rome, where they were crowned emperors by the pope.

The German Empire stretched from the Baltic and the North Sea to the Adriatic and the Tyrrhenian. Such a distance, with a lot of mountains in between, forced emperors to spend long periods on the road. An emperor might be in Italy, quarrelling with the pope over ecclesiastical appointments, when an outbreak of civil war in Germany made him hurry northwards; after settling that crisis, he might have to scuttle back across the Alps to confront the rebellious cities of Lombardy or go even further south to deal with a military threat from Byzantium or the Norman kingdom of Sicily. Even so, emperors managed to find time for outside interests such as campaigning in Poland and participating in four of the Crusades. A predictable consequence of such frenetic activity was the neglect of Italy.

The emperors had their judicial and fiscal institutions in Italy; they also had their supporters among the magnates and bishops, whom they relied on for the administration of the cities. Yet the absence of their overlord enfeebled the institutions and the bishops and encouraged magnates to do what they liked to do anyway: plot and switch allegiances. Such a structure was ill-equipped to administer the new Italy of the eleventh century, in which agricultural wealth, the expansion of trade and a rise in population were transforming societies and economies. The growth and prosperity of the cities gave their citizens the desire and self-confidence to run the affairs of their own communes. Unwilling to accept that they should remain loyal to an absentee foreigner with doubtful rights of sovereignty, they were soon electing their own leaders, running their own courts and raising their own militias. The emperors, distracted by incessant wars in Germany, made concessions that left the communes virtually autonomous. By the late eleventh century their rule over the Lombard and Tuscan cities had become almost nominal.

Frederick Barbarossa (Redbeard), the Duke of Swabia who became emperor in 1155, was determined to reverse the drift. A relentless warrior, with grandiose notions of his rights and his dignity, he later became renowned as a symbol of Teutonic unity, a hero to German romantics and an inspiration for Adolf Hitler, who code-named his invasion of Russia ‘Operation Barbarossa’. He regarded the Ottos as successors to the Caesars and himself as successor to the Ottos. As he claimed his position to be equivalent to that of Augustus, he considered the kings of France and England to be inferior rulers. As for Italy, he was intent on reclaiming the so-called ‘regalian rights’ which lawyers in Bologna conveniently assured him he possessed. These included the rights to appoint officials in the cities, to receive taxes on fish and salt and to collect money from tolls and customs. He wanted the cash and was determined to get it; he also enjoyed the prestige acquired from the submission of others.

The defiance of Milan, the largest Italian city, inspired Barbarossa to invade Italy, which he did half a dozen times. His pretext – and perhaps it was a little more than a pretext – was that he was coming to the rescue of those pro-imperial towns, such as Como and Lodi, which earlier in the century had been devastated by the Milanese. He captured Milan in 1162 and destroyed it. He also obliterated the town of Crema, one of its allies, after besieging it with exceptional brutality: hostages from Crema were tied to the front of his siege towers so that the defendants could not avoid hitting their relatives and fellow citizens with arrows.

Barbarossa’s actions led to the foundation of the Lombard League, formed by sixteen cities in 1167 to defend themselves against his imperial armies. An early confrontation was avoided, however, when more urgent matters forced the emperor to return to Germany, and he did not come back at the head of a new army for several years. Despite the defection of a couple of cities, the League won a great victory against him in 1176 at Legnano near Milan, its infantry forcing Barbarossa’s German cavalry from the field. It was a historic moment for the peninsula, perhaps the most united moment between the death of Theodoric and the creation of modern Italy. When patriots of the nineteenth century scoured their history for heroic events to depict, Legnano was a popular choice for literature and painting; it also inspired one of Verdi’s least memorable operas, La battaglia di Legnano, in which the chorus opens the evening with the words

Long live Italy! A holy pact

binds all her sons together.

At last it has made of so many

a single people of heroes!

Unfurl the banners in the field,

unconquered Lombard League!

And may a shiver freeze the bones

of fierce Barbarossa.

His humiliating defeat forced Barbarossa to negotiate, and at the Treaty of Constance in 1183 he conceded the rights of the communes to elect their own leaders, make their own laws and administer their own territories. Concessions made by his opponents were nominal or unimportant: among them were an oath of allegiance and a promise to give a sum of money to future emperors as they proceeded to Rome for their coronations. As the historian Giuliano Procacci noted, ‘the communes recognized the overall sovereignty of the emperor, but kept the sovereign rights they held’. Barbarossa died seven years later, drowned in an Anatolian river on his way to join the Third Crusade, but his Italian ambitions lived on in the person of his grandson, the Emperor Frederick II, who made equally futile attempts to cow the cities of northern Italy.

The wars between Barbarossa and the communes were part of a longer and wider struggle between the Holy Roman emperor and the papacy, which had supported the Lombard League. As with so many conflicts on Italian soil, this one thus became internationalized, several popes calling in German and French princes to assist their cause. Competing factions in the Italian communes soon acquired labels of bewildering foreign origin. Papal supporters were known as Guelphs, called after the Bavarian Welf family that produced Otto IV, briefly an emperor in the early thirteenth century, as well as, later and less relevantly, the Hanoverian kings of Great Britain. Their opponents, the pro-imperial Ghibellines, took their appellation from an even more obscure source, the Salian and later Hohenstaufen town of Waiblingen, a name sometimes used to denote members of the house of Swabia. In their endless medieval struggles, however, Italian Guelphs and Ghibellines were motivated far more by local factors than by remote loyalties to popes and German emperors.

When Pope Leo III crowned Charlemagne, it was clear that the Franks, who had rescued the papacy from the Lombards, were the senior partners in the alliance. Yet Leo’s successors tried to reverse the roles by claiming the right to choose who would be emperor. By the eleventh century they were insisting that the emperors acknowledge they received their thrones from the pope, who, as Christ’s vicar on earth, was the highest authority in Christendom. Power was involved along with pride and prestige. Gregory VII, pope (1073–85) and later saint, insisted that only he had the right to invest the clergy with abbeys, bishoprics and other ecclesiastical offices: secular rulers who disobeyed him were excommunicated. The Emperor Henry IV, who planned to continue the policy of his father (Henry III) of appointing and dismissing popes as well as bishops, reacted by deposing Gregory and calling him ‘a false monk’. In retaliation the pope excommunicated the emperor and encouraged his subjects to rebel. Alarmed by threats to his rule in Germany, a contrite Henry then apologized to the pope, waiting for three days in the snow outside the castle of Canossa until Gregory finally absolved him from excommunication. Within three years, however, they were again at odds, and Henry was deposed and excommunicated once more. This time he responded by seizing Rome and setting up an anti-pope who crowned him emperor, but he was soon expelled by the real pope’s Norman allies, who burned much of the city. The feud between Henry and Gregory was not a unique one: these medieval centuries abound with examples of emperors dethroning popes and of popes deposing and excommunicating emperors as well as other monarchs.

Another ingredient in the dispute between pope and emperor was the status of the Norman kingdom of Sicily. The south of Italy was already very different from the north, more rural and feudal, more ethnically varied, its life determined by the Mediterranean and its peoples in a way unknown to the cities of the Po Valley with their ties to Europe beyond the Alps. Under authoritarian rulers, who liked to direct the economy themselves, and living uncomfortably beside a feudal baronage, the towns had little chance to prosper as their counterparts could do further north; the few that had recently flourished, such as the port of Amalfi with its merchants in Egypt and on the Bosphorus, soon withered. Like the north, the south had its Romans, Lombards and Franks, but it also contained large numbers of Byzantine Greeks and Muslim Arabs as well as a significant Jewish minority. This multicultural, multi-confessional amalgam was unexpectedly welded into a kingdom by a small band of knights from Normandy whose descendants ruled it, flamboyantly and on the whole successfully, for nearly 200 years.

Norman adventurers, seeking work as mercenary soldiers, had begun arriving in the south early in the eleventh century. Pope Benedict VIII hired some of them to fight the Byzantines in Apulia, and before long a few of the knights, notably the remarkable Hauteville brothers, were receiving lands from grateful employers. Fearing that these Normans were becoming too strong, a later pope led an army against them but was defeated and taken prisoner by one of the five Hautevilles, Robert Guiscard, in 1053. Making the best of it, the papacy agreed soon afterwards that, in return for recognizing papal sovereignty over the south, Robert Guiscard could call himself ‘Duke of Apulia and Calabria and future Duke of Sicily’. The adjective ‘future’ soon became redundant when the new duke, assisted by his equally talented younger brother Roger, advanced down Calabria and invaded Sicily in 1061. Thereafter, Robert Guiscard concentrated on conquering the mainland north, capturing Bari and ending Byzantine rule there in 1071, while Roger (later known as ‘the Great Count’) overcame the Arabs of Sicily, taking Palermo in 1072 and completing his conquest of the island in 1090. After the deaths of the two brothers, the Great Count’s son, another Roger, united the Hauteville territories and, following the capture of another pope, was recognized as Roger II, King of Sicily.

The new king was one of the finest rulers of the Middle Ages, a broadminded and farsighted man of wide culture and much administrative ability. He refused to join the Second Crusade because religious toleration was fundamental to his rule, and he insisted that the laws and customs of the peoples of his kingdom should be respected. Fluent in Greek and Arabic, he presided over the most intellectual and cosmopolitan court in Europe, and the architecture he loved – a blend of Saracen, Norman and Byzantine – is still visible in Palermo, in the Palatine chapel with its mosaics and in the red domes of the church of San Giovanni degli Eremiti. He returned Sicily to the prosperity and influence it had not enjoyed since the days of the ancient Greeks – and to which it would not return again. He made of the Mediterranean’s largest island a microcosm of what the sea might be but very rarely is, a space where cultures, creeds and peoples meet in a climate of mutual tolerance and respect.

The popes treated the Normans much as they treated the emperors: cajoling and pleading when they needed them, fighting and trying to depose them when they did not. Robert Guiscard and Roger II both suffered excommunication. When the Hautevilles and the Hohenstaufen (Barbarossa’s family) became dynastically united in 1186, the hostility became almost permanent. Roger was succeeded by his son William I, another talented and successful Hauteville, unjustly known by his foes among the barons as William the Bad, and by his grandson, William II, called ‘the Good’ because he was more lenient to those perennially annoying subjects. Since Barbarossa after Legnano was no longer a threat to Italy, the second William decided to marry his aunt Constance to the emperor’s heir, the future Henry VI; as his own marriage was childless, a son of this union might thus add the crown of Sicily to the titles of King of Germany, King of Italy and Holy Roman emperor. The prospect of an emperor ruling lands both north and south of the expanding papal states naturally alarmed Pope Celestine III, who first promoted a rival claimant (an Hauteville bastard) to the Sicilian throne and then tried to thwart Henry’s plan to have his son Frederick elected King of Germany. He failed when Frederick was chosen by the electors at the age of two in 1196, but the deaths of the boy’s parents before he was four, together with Constance’s choice of the next pope (Innocent III) as her son’s guardian, postponed an inevitable struggle.

The infant became the charismatic Frederick II, a monarch whose cultural range makes his fellow rulers of the period seem brutal, boorish and philistine in comparison. Hailed as stupor mundi (‘the amazement of the world’), he was lauded in his time as a linguist, law-giver, builder, soldier, administrator and scientist; as an ornithologist he wrote a masterly book on falconry and dismissed the notion that barnacle geese were hatched from barnacles in the sea – an example of deductive reasoning rather than observation because he had no opportunity of studying the breeding habits of the geese inside the Arctic Circle. Yet the adulation, like the appellation, was excessive. The comparison with contemporary kings may stand, but he was not as wise a ruler or as cultured a man as his maternal grandfather, Roger II. He was justly famous as a champion of religious tolerance, yet his skills as a builder, architect and linguist have been exaggerated. In any case, whatever his talents, he failed to solve the three great inherited problems of his position: relations with the papacy, relations with the Lombard cities, and the relationship between Sicily and the empire.

Frederick antagonized the papacy early in his reign by crowning his baby son King of Sicily and, a few years later, making sure he was elected King of Germany. When he himself was crowned emperor in 1220, at the age of twenty-five, he assured the papacy that the crowns would remain legally separated. Yet the assurance did not convince a subsequent pope, Gregory IX, once a friend of St Francis and St Dominic but now a dogmatic and irascible leader of the Church. In 1227 he excommunicated Frederick after an outbreak of plague had forced the emperor to abandon a crusade; when the expedition was resumed a year later, the pope was so enraged that an excommunicant was leading it that he launched an invasion of Sicily while its king and his army were away campaigning triumphantly for Christendom. Frederick soon returned from the Holy Land, where he had crowned himself King of Jerusalem, defeated the papal armies and forced Gregory to come to terms and absolve him from excommunication.

The truce between the two men lasted for almost a decade after 1230, but the pope did not relinquish his ambitions to remove the Hohenstaufen from Sicily and to promote a new dynasty for the empire. Frederick’s invasion of Sardinia in 1239 gave him a pretext to excommunicate the emperor once again and build alliances with the pro-Guelph cities of the north. Gregory died in 1241, yet his vendetta was continued, with matching vindictiveness, by a successor, Innocent IV, who deposed Frederick, called him a precursor of the anti-Christ and urged the German electors to supply a new emperor.

Stupor mundi may have been unlucky in his relations with the papacy but he was unwise in his dealings with the Lombard cities. Claiming that northern Italy legally belonged to him, he was determined to succeed where Barbarossa, his paternal grandfather, had failed. In 1226 he summoned an imperial assembly to Cremona, most loyal of Ghibelline towns, and announced his intention ‘to restore regalian rights’. His ambitions predictably led to a revival of the Lombard League, and most of the Po Valley cities banded together to resist him for the last quarter-century of his life. Frederick defeated the League at the Battle of Cortenuova in 1237 but then overplayed his hand by demanding an unconditional surrender, which the cities refused to give him; the following year he was humiliated by his failure to capture Brescia after a lengthy siege. Despite military successes in 1240–41, when he captured parts of the Papal States, and in 1246, when he suppressed a rebellion in the south, the campaigns achieved nothing durable. Even more humiliating than Brescia was the siege of Parma in 1248, when the apparently beleaguered garrison unexpectedly stole out of the town and ransacked Frederick’s camp while he was out hunting.

The emperor died in 1250 and, after the brief reign of his son Conrad, his southern territories were claimed by his bastard child Manfred. Another talented descendant of the Hautevilles, Manfred was a poet, a scientist and a diplomat wiser than his father in his dealings with northern Italy. Yet Frederick’s death had not halted the papacy’s efforts to eliminate the house of Hohenstaufen and to find a new monarch for the kingdom of Sicily. In 1266, after the entreaties of several popes, Charles of Anjou, a brother of the French king, victoriously invaded: Manfred was killed in battle, and the last male Hohenstaufen, Conrad’s teenage son Conradin, was executed.

Charles made himself unpopular in Sicily, chiefly by transferring his capital from Palermo to Naples, and he was ejected by the islanders following the uprising in 1282 known as the Sicilian Vespers. In his place the throne was offered to King Peter of Aragon, whose wife was a daughter of Manfred. Peter’s acceptance and reign may have given some solace to supporters of the Hohenstaufen, but Aragonese rule presaged the long decline of the island. Already cut off from north Africa and the Arab world, it was now detached from France and Italy, although over the centuries the southern mainland – known as ‘continental Sicily’ – was from time to time reunited with island Sicily to be called eventually the Kingdom of the Two Sicilies. Yet from the end of the thirteenth century the island was effectively an outpost of Spain, tied torpidly to Iberia for over 400 years. Like Sardinia, it received viceroys but little attention from its Hispanic rulers.

Frederick’s rule had resulted in the extinction of his dynasty and the impoverishment of Sicily, which had to pay for his wars. Another casualty was the idea of uniting Italy under a single ruler, which is what he wanted and which no one tried to make a reality again for another six centuries. The beneficiaries of his failure were the cities of Tuscany and the north, which could now pursue their cultural and communal development – as well as their local rivalries – without much external interference. The defeat of a cultured monarch of the south thus led to a cultural efflorescence of the north.