He was the son of emperor Henry V and Constance of Sicily. He was born in December 1994, and in 1196 he was elected as "King of the Germans" (the title for the heir to the Empire) -- an election which was challenged by both his uncle Philip of Swabia and by Otto of Brunswick. He was 2, and travelling from Italy to Germany when news came of his father's death. He was taken back to Italy. There his mother, queen in her own right of Sicily, had him crowned as king, with herself as his regent, then severed all ties with the Empire, sent home all the German counsellors, and on her son's behalf renounced his claims to the German kingship and to the Imperial throne. In 1198 Constance died,a dn the pope, Innocent II, became Frederick's guardian during his minority. Otto was crowned emperor Otto V by Innocent in 1209, but by 1211 pope and emperor had fallen out, the one had excommunciated the other (for interfering in Italian politics), and Innocent supported a faction who elected Frederick King of the Germans in absentia in September 1211. He was elected again in 1212, and crowned in December 1212 and again in 1215. He was, however, recognised only in the southern German lands: the North remained Guelph in its sympathies and Otto was able to hold royal and imperial authority. The 1215 coronation was by the pope but, despite Otto's death in 1218, it was not until 1220 that Frederick was crowned Emperor, by Innocent's successor Honorius III. In the meantime Frederick had married, to Constance of Aragon (widow of Emeric of Hungary and mother of the infant king Ladislas), and in 1211 their son, Henry, was born, who, on his father's elevation to the Imperial throne, was duly elected King of the Germans as his heir. Constance, regrettably did not long survive Frederick's elevation and died in 1222. On his coronation as Emperor, Frederick swore to go on crusade, and he left Germany for his Sicilian kingdom, ostensibly to prepare. In 1225, now widowed, he married Yolande of Jerusalem and sought to wrest control of the kingdom from her father, John of Brienne. However, he did not actually set off, and the new pope, Gregory IX, excommunciated him for failing to honour his vow. In fact Frederick, from the time of his coronation, had showed a broad-minded attitude towards Islam, including enlisting Muslim soldiers for his Sicilian army. Ho was, however, also inhibited from setting off by an outbreask pf plague. He embarked in 1228, still excommunicate, which meant that the Church could not support him. Gregory promply excommunicated him a second time, but Frederick proceeded to Palestine, where he entered into neogtiations with the local Muslim ruler (who was nervous about his local relatives and wanted peace with Christendom for the time being). A truce was arranged, and Frederick moved to have himself crowned King of Jerusalem (although technically he had no right: Yolade had died, and the true king was their infant son, Conrad. The baronage of Outremer resisted Frederick's attempts to govern, and he had, in any event, to return to Europe. He was able to have his excommunication lifted by the pope (Gregory IX) in 1231, but this was more a matter of political expediency -- Henry his son had allied with the Lombards and rebelled. The rebellion was suppressed -- Henry was imprisoned, and Conrad, whom Frederick had tried to supercede in Jerusalem, was made the new Imperial heir. In 1237 Frederick finally crushed the rebels but his refusal to accept anything short of total and abject surrender made the pope fear he intended to impose Imperial control throughout Italy. Gregory imposed a new excommunciation in 1239; Frederick replied by sending his son, Enzio, with and army, into northern Italy. A war continued for several years -- Gregory died in 1240, and Frederick withdrew; Roman troops renewed their attacks, and Frederick retaliated. A new pope, Innocent IV, was elected in 1243, and the war was renewed even more fiercely by both sides, until in 1245 Innocent declared Frederick deposed as Emperor (citing his friendship with the Muslims), and apparently plotted to have him killed, so that he could place his own candidate on the Imperial throne. This was Heinrich Raspe and in 1246 he was declared king in opposition to Conrad. he was able to defeat an army of Conrad's in August 1245, but died the next year. The new anti-king was William II, Count of Holland. Frederick fought on, but in June 1247 the city of Parma expelled Imperial officers and Frederick was obliged to besiege it. In a battle in the succeeding February the Emperor lost his treasury and support for him began to wither. H ewas able to rebuild, but many cities found the fiscal price so high that they too resisted. In 1249 he fired his chief advisor, allegedly for embezzlement; in May his son Enzio was captured, and another son, Richard of Chieti, was killed. Frederick fell ill. The Italian campaign turned against him, although Conrad, in Germany, was holding off William of Holland. In December 1250, weakeend by Dysentery, Frederick died. Conrad was his heir, but his dynasty had been weakened, and Conrad was to be the last of his family's emperors.