The era of the Hohenstaufen is perhaps the fittest point at which to turn aside from the narrative history of the Empire to speak shortly of the legal position which it professed to hold to the rest of Europe, as well as of certain duties and observances which throw a light upon the system it embodied. This is not indeed the era of its greatest power: that was already past. Nor is it conspicuously the era when its ideal dignity stood highest: for that remained scarcely impaired till three centuries had passed away. But it was under the Hohenstaufen, owing partly to the splendid abilities of the princes of that famous line, partly to the suddenly-gained ascendancy of the Roman law, that the actual power and the theoretical influence of the Empire most fully coincided. There can therefore be no better opportunity for noticing the titles and claims by which it announced itself the representative of Rome's universal dominion, and for collecting the various instances in which they were (either before or after Frederick's time) more or less admitted by the other states of Europe. The territories over which Barbarossa would have declared his jurisdiction to extend may be classed under four heads:-- First, the German lands, in which, and in which alone, the Emperor was, up till the death of Frederick the Second, effective sovereign. Second, the non-German districts of the Holy Empire, where the Emperor was acknowledged as sole monarch, but in practice little regarded. Third, certain outlying countries, owing allegiance to the Empire, but governed by kings of their own. Fourth, the other states of Europe, whose rulers, while in most cases admitting the superior rank of the Emperor, were virtually independent of him. [Sidenote: Limits of the Empire.] Thus within the actual boundaries of the Holy Empire were included only districts coming under the first and second of the above classes, i.e. Germany, the northern half of Italy, and the kingdom of Burgundy or Arles--that is to say, Provence, Dauphiné, the Free County of Burgundy (Franche Comté), and Western Switzerland. Lorraine, Alsace, and a portion of Flanders were of course parts of Germany. To the north-east, Bohemia and the Slavic principalities in Mecklenburg and Pomerania were as yet not integral parts of its body, but rather dependent outliers. Beyond the march of Brandenburg, from the Oder to the Vistula, dwelt pagan Lithuanians or Prussians[201], free till the establishment among them of the Teutonic knights. [Sidenote: Hungary.] Hungary had owed a doubtful allegiance since the days of Otto I. Gregory VII had claimed it as a fief of the Holy See; Frederick wished to reduce it completely to subjection, but could not overcome the reluctance of his nobles. After Frederick II, by whom it was recovered from the Mongol hordes, no imperial claims were made for so many years that at last they became obsolete, and were confessed to be so by the Constitution of Augsburg, A.D. 1566[202].