Frederick II, Holy Roman Emperor

Frederick was born on 26 December 1194 in Jesi, a small town in the March of Ancona in central Italy. His mother, Constance of Sicily, was already forty and had never borne a child, so she chose to deliver her son in a tent pitched in the town square, inviting the local matrons to witness the birth and silence any doubts about its legitimacy ^[1]. His father was Emperor Henry VI of the Hohenstaufen house, who had conquered the Norman Kingdom of Sicily in Constance's name only weeks earlier.

Both parents died before the boy turned four. Henry VI succumbed to fever at Messina in 1197, and Constance followed in 1198, but not before having her son crowned King of Sicily and placing him under the guardianship of Pope Innocent III ^[2]. The arrangement was less protective than it sounded. During Frederick's childhood, German captains, papal legates, and Sicilian barons fought over the island, and the young king grew up in Palermo with limited supervision and scant funds.

That unusual upbringing shaped him. Palermo remained a city of Greek, Arabic, Latin, and Norman French speakers, heir to the mixed court culture of the Norman kings. Frederick absorbed languages, an appetite for argument, and a curiosity about the natural world that never left him. Later admirers credited him with fluency in six tongues, a claim impossible to verify but consistent with the polyglot city that raised him ^[1]. Anyone asking who was Frederick II, Holy Roman Emperor, should begin here: he was a Sicilian before he was a German, and he governed accordingly.

Frederick's route to the imperial throne opened through the misfortunes of others. After Henry VI's death, the German princes split between Frederick's uncle Philip of Swabia and the Welf candidate Otto of Brunswick. Philip was murdered in 1208, and Otto IV won the crown, only to invade papal territory and Sicily, provoking Innocent III to excommunicate him ^[2]. The pope then turned to his teenage ward as a counterweight.

In 1212 the seventeen year old crossed the Alps with a small escort, evading Otto's allies, and was elected king of the Romans by a faction of German princes at Frankfurt. His prospects looked thin until July 1214, when his ally King Philip II of France crushed Otto's coalition at the Battle of Bouvines ^[3]. The victory settled the German succession. Frederick was crowned at Aachen in 1215, where he took a crusading vow that would haunt his relations with Rome for the next fifteen years.

On 22 November 1220, Pope Honorius III crowned Frederick Holy Roman Emperor in St Peter's Basilica ^[2]. He now held, in personal union, the empire north of the Alps and the wealthy Sicilian kingdom to the south, an encirclement of the Papal States that every pope of his lifetime regarded as an existential threat. Managing that suspicion, and eventually failing to manage it, became the central problem of his reign.

Any account of Frederick II, Holy Roman Emperor achievements has to start with Jerusalem. Excommunicated by Pope Gregory IX in 1227 for delaying his crusade after an epidemic struck his fleet, Frederick sailed anyway the following year. Instead of fighting, he negotiated. In February 1229 he concluded the Treaty of Jaffa with the Ayyubid sultan al-Kamil, which returned Jerusalem, Bethlehem, Nazareth, and a corridor to the coast to Christian control for ten years ^[4]. In March 1229 he placed the crown on his own head in the Church of the Holy Sepulchre, since no cleric would perform the ceremony for an excommunicate. It was the only crusade of the era to recover the holy city without a major battle.

His legislative work proved more durable. The Constitutions of Melfi of 1231, also called the Liber Augustalis, reorganized the Kingdom of Sicily into one of the most centralized states in medieval Europe, with salaried royal justices, restrictions on baronial and clerical courts, regulated medical licensing, and a fiscal system that made the kingdom the financial engine of his wars ^[5]. Historians have long debated how far the code anticipated later state building, but its ambition was unmatched in its century.

Frederick also founded the University of Naples in 1224, the first European university established by a secular ruler rather than by charter from pope or guild, created to train administrators loyal to the crown rather than to the church ^[6]. His court patronized the Sicilian School of poets, whose experiments in the vernacular produced the sonnet form and drew praise from Dante. And his own book, De arte venandi cum avibus (On the Art of Hunting with Birds), rested on decades of direct observation of raptors; ornithologists still note its corrections of Aristotle, made on the evidence of Frederick's own experiments ^[7].

Frederick married three times, each match a political instrument. His first wife, Constance of Aragon, a widow ten years his senior, brought knights and legitimacy to the insecure young king in 1209 and bore his heir Henry before dying in 1222 ^[1]. In 1225 he married Isabella II (Yolande) of Brienne, the teenage heiress of the Kingdom of Jerusalem, which gave him the legal claim he exploited on crusade; she died in 1228 shortly after giving birth to his son Conrad. His third wife, Isabella of England, sister of King Henry III, married him in 1235 and died in 1241 ^[2].

Alongside the marriages ran a long series of liaisons that produced numerous illegitimate children, several of whom he trusted with real power. Enzio became king of Sardinia and one of his best commanders, and Manfred, son of Bianca Lancia, ultimately ruled Sicily after Frederick's death ^[1]. Family loyalty had limits in the other direction: when his eldest son Henry, left as king in Germany, rebelled in 1234 and 1235, Frederick deposed him and kept him imprisoned in southern Italy until Henry died in 1242.

The emperor's personal habits fed his legend. He traveled with a menagerie that included elephants, camels, leopards, and a giraffe, kept Muslim retainers and dancers at court, and settled thousands of Sicilian Muslims at Lucera in Apulia, where they served as farmers and loyal soldiers exempt from local church pressure ^[4]. Hostile chroniclers, above all the Franciscan Salimbene of Adam, recorded stories of cruel experiments on prisoners; modern historians treat these tales as polemic rather than reliable fact, while agreeing that Frederick could be coldly ruthless toward rebels and suspected traitors ^[1].

From the mid 1230s the reign narrowed into one grinding conflict with the papacy and the city leagues of northern Italy. Frederick smashed the Lombard League at Cortenuova in November 1237, parading the captured Milanese carroccio, the city's war wagon, through the streets of Cremona ^[3]. The triumph proved hollow. Milan refused his terms, the war dragged on, and in March 1239 Gregory IX excommunicated him a second time, opening a propaganda battle in which papal letters called him the beast of the Apocalypse and imperial circulars answered in kind ^[2].

The struggle consumed everything. In 1241 imperial and Pisan ships captured a fleet carrying prelates to a papal council, an act that shocked even sympathizers. Gregory's successor Innocent IV fled to Lyon and there, at the Council of Lyon in July 1245, declared Frederick deposed, absolving his subjects of their oaths ^[8]. Anti-kings were raised against him in Germany, plots surfaced among his closest officials in Italy, and in 1249 his longtime minister Pier della Vigna, accused of treason, died in prison, an episode Dante later placed in the Inferno.

Military fortune turned as well. His army suffered a damaging defeat at Parma in 1248 when the besieged citizens overran his camp, and his son Enzio was captured by the Bolognese in 1249 and never released ^[3]. Frederick was preparing yet another campaign when dysentery struck him in Apulia. He died on 13 December 1250 at Castel Fiordimonte near Lucera, thirteen days short of his fifty sixth birthday, reportedly in the habit of a Cistercian monk, and was buried in a porphyry sarcophagus in Palermo Cathedral, where his tomb remains ^[1].

The Hohenstaufen edifice collapsed quickly. Frederick's legitimate heir Conrad IV died in 1254, Manfred fell in battle at Benevento in 1266 against the papally sponsored Charles of Anjou, and in 1268 Frederick's sixteen year old grandson Conradin was defeated and publicly beheaded in Naples, ending the dynasty in the male line ^[2]. In Germany the decades after 1250 became known as the Great Interregnum, a stretch of contested and absentee kingship that lasted until Rudolf of Habsburg's election in 1273.

The man outlived his house in imagination. Chroniclers had already dubbed him stupor mundi, and popular prophecy refused to accept his death: legends of a sleeping emperor who would return to reform church and empire circulated for centuries, later migrating to his grandfather Barbarossa ^[1]. In the early twentieth century the German historian Ernst Kantorowicz published a monumental and openly admiring biography that cast Frederick as a proto-modern ruler; the book's reception, including its embrace by German nationalists, has itself become a case study in how history gets used ^[9].

Scholars today draw a more measured picture. David Abulafia's influential 1988 study argued that Frederick was in most respects a conventional medieval king whose reputation for radical modernity says more about his admirers than about him ^[1]. Yet even skeptical assessments concede the range: lawgiver of Melfi, founder of Naples, negotiator of Jerusalem, patron of the sonnet, author of a falconry treatise grounded in observation. Among the basic Frederick II, Holy Roman Emperor facts, perhaps the most telling is that both the extravagant praise and the apocalyptic hatred began in his own lifetime, and any Frederick II, Holy Roman Emperor biography still has to navigate between them.