The Great Interregnum
The clergy had castles, cities and even provinces bestowed to them. Why? Because the monarch or king hoped that the church would civilize the barbarous countries over which they reigned and would in turn secure a body of loyal men for him.
The clergy took their power seriously and a new Pope deposed Holy Roman Emperor Frederick II, head of the House of Hohenstaufen and kingdom of Prussia: Innocent IV, a member of a noble Imperial family in 1245. Frederick was a threat to them because in 1220 at age 25, he was crowned emperor in St Peter’s, Rome, by Pope Honorius III. Philosophically, this made him the earthly head of Christ’s people on earth and overlord of northern Italy. He had originally gained rule of southern Italy and Sicily at age 14 on Rome’s doorstep, which put him in the sights of the popes.
Innocent IV was elected in June 1243. The emperor was initially happy with this election but soon became Frederick’s fiercest enemy. That very summer, Frederick stood to lose his main stronghold near Rome and besieged the city. Innocent convinced the rebels to sign a peace treaty, but after Frederick withdrew his garrison, a cardinal had them slaughtered. Frederick was incensed. Innocent IV set a plot to kill Frederick in motion, but the plotters were unmasked and then blinded, mutilated and burnt alive or hanged. Frederick sustained many attacks after that.
When Pope Innocent IV heard about the death of Frederick II in Germany, he was delighted. “Let heaven exult and the earth rejoice," he proclaimed in a message to the Sicilian bishops.
The emperor’s death also ushered in the Great Interregnum (1250–73), a period of internal confusion and political disorder and a period of temporary suspension of the usual functions of government or control.
Now contests between Popes and Princes—there were six princes claiming to be emperor of Germany—reduced the empire to anarchy. Succession disputes meant that no candidate received enough votes to become emperor. This unique set of facts is referred to as the Babenberg Legacy, as Frederick was the fifth and last Austrian duke from the House of Babenberg. The beginning of this era ushers in tension between two kings: Rudolf I crowned in 1273 as the first Roman-German king of the Habsburg dynasty and Ottokar II Přemyslid, King of Bohemia, who refused to recognize him.