On returning to Germany, Frederick found enough to do. He restored the internal peace and security of the country with a strong hand, executing the robber-knights, tearing down their castles, and even obliging fourteen reigning princes, among whom was the Archbishop of Mayence, to undergo what was considered the shameful punishment of carrying dogs in their arms before the Imperial palace. By his second marriage with Beatrix, Princess of Burgundy, he established anew the German authority over that large and rich kingdom; while, at a diet held in 1156, he gave Bavaria to Henry the Lion, and pacified Henry of Austria by making his territory an independent Dukedom. This was the second phase in the growth of Austria. [Sidenote: 1156. BARBAROSSA'S RULE IN GERMANY.] Henry the Lion, however, was more a Saxon than a Bavarian. Although he first raised Munich from an insignificant cluster of peasants' huts to the dignity of a city, his energies were chiefly directed towards extending his sway from the Elbe eastward, along the Baltic. He conquered Mecklenburg and colonized the country with Saxons, made Lübeck an important commercial center, and slowly Germanized the former territory of the Wends. Albert the Bear, Count of Brandenburg, followed a similar policy, and both were encouraged by the Emperor, who was quite willing to see his own sway thus extended. A rhyme current among the common people, at the time, says: "Henry the Lion and Albert the Bear, Thereto Frederick with the red hair, Three Lords are they, Who could change the world to their way." The grand imperial character of Frederick, rather than what he had actually accomplished, had already given him a great reputation throughout Europe. Pope Adrian IV. endeavored to imitate Gregory VII.'s language to Henry IV. in treating with him, but soon found that he was deserted by the German Bishops, and thought it prudent to apologize. His manner, nevertheless, and the increasing independence of Milan, called Frederick across the Alps with an army of 100,000 men, in 1158. Milan, then surrounded with strong walls, nine miles in circuit, was besieged, and, at the end of a month, forced to surrender, to rebuild Lodi, and pay a fine of 9,000 pounds of silver. Afterwards the Emperor pitched his camp on the Roncalian fields, with a splendor before unknown. Ambassadors from England, France, Hungary and Constantinople were present, and the Imperial power, almost for the first time, was thus recognized as the first in the civilized world.