Grandson of Frederick I, Frederick II inherited the Sicilian crown as a very young child from his parents, Emperor Henry VI of the Hohenstafen dynasty and Constance of Sicily. During his reign as Holy Roman Emperor, Frederick earned the name of "stupor mundi" thanks to his charisma and exceptional gifts. Throughout his lifetime, Frederick refused to be subjected to the Papal powers, and sought instead to incorporate Italy into the Empire.
Under the protectorate of Innocent III, Frederick passed his youth in Palermo. In 1212 he was called to Germany to assume the imperial crown. Frederick remained in Germany until 1220, stabilizing his domain there. He then returned to Sicily, where he reorganized the kingdom and brought it under tight control, establishing peace in the realm. Frederick was an intellectual and a patron of the arts and sciences; his cosmopolitan court united the cultures of the Christian, Muslim and Jewish worlds.
Dissension soon arose between the young Emperor and Popes Honorius III and Gregory IX for his delay in fulfilling his promise to undertake a Crusade to the Holy Land. Frederick was excommunicated by Gregory, and when he finally did depart to the East in 1228, he regained the city of Jerusalem from the Muslims by diplomacy rather than arms. After being crowned King of Jerusalem, he returned to Sicily in 1230, where he discovered and defeated the papal troops.
From the 1230s onwards, Frederick concentrated almost solely on strengthening his position in Northern Italy. Pope Gregory rightly feared that the Papal States would be caught between Frederick's Sicily to the South and his Empire to the North. Tensions and hostilities increased, until Gregory excommunicated the Emperor once again (1239) and the Emperor went so far as to attack Rome itself. In the following years, Frederick demonstrated his unflagging spirit by tenaciously defending his Italian interests against the ruthless strategems of the Papacy. After some reversals in 1248, Frederick was once again gaining the upper hand when, in 1250, he unexpectedly died in Fiorentino, Italy.
Frederick II is mentioned in three tales of the Decameron: I.7, II.6, and V.5. The first contains a reference to the liberality of Frederick II, the second speaks of Manfred's rule of Sicily after the death of Frederick, and the last mentions one of Frederick's campaigns in Northern Italy.
(R.P/N.S.) Adapted from Kamp, Norbert, s.v. Federico II di Svevia. Vol. 45. Dizionario biografico degli italiani, Roma: Istituto della Enciclopedia italiana, 1960. pp. 743-758; Manselli, Raoul. s.v. Federico II. Vol. 2. Enciclopedia dantesca, Roma: Istituto della Enciclopedia italiana, 1970-78. pp. 825-828; Toynbee, P. Dictionary of Proper Names and Notable Matters in the Works of Dante. Oxford: Clarendon, 1968. pp. 229-231.