In Berlin the spirit of revolution became as marked as in Vienna. The King resisted the demands of the people, who soon came into conflict with the soldiers, a fierce street fight breaking out which continued with violence for two weeks. The revolutionists demanded the removal of the troops and the formation of a citizen militia, and the king, alarmed at the dangerous crisis in affairs, at last assented. The troops were accordingly withdrawn, the obnoxious ministry was dismissed, and a citizen-guard was created for the defence of the city. Three days afterwards the king promised to govern as a constitutional monarch, an assembly was elected by universal suffrage, and to it was given the work of preparing a constitution for the Prussian state. Here, as in Austria, the revolutionists had won the day and irresponsible government was at an end. Elsewhere in Germany radical changes were taking place. King Louis of Bavaria, who had deeply offended his people, resigned in favor of his son. The Duke of Hesse-Darmstadt did the same. Everywhere the liberals were in the ascendant, and were gaining freedom of the press and constitutional government. The formation of Germany into a federal empire was proposed and adopted, and a National Assembly met at Frankfort on May 18, 1848. It included many of the ablest men of Germany. Its principal work was to organize a union under an irresponsible executive, who was to be surrounded by a responsible ministry. The Archduke John of Austria was selected to fill this new, but brief imperial position, and made a solemn entry into Frankfort on the 11th of July. [=The Schleswig-Holstein Affair=] All this was not enough for the ultra radicals. They determined to found a German republic, and their leaders, Hecker and Struve, called the people to arms. An outbreak took place in Baden, but it was quickly suppressed, and the republican movement came to a speedy end. In the north war broke out between Denmark and Schleswig-Holstein, united duchies which desired to be freed from Danish rule and annexed to Germany, and called for German aid. But just then the new German Union was in no condition to come to their assistance, and Prussia preferred diplomacy to war, with the result that Denmark came out victorious from the contest. As will be seen in a later chapter, Prussia, under the energetic leadership of Bismarck, came, a number of years afterwards, to the aid of these discontented duchies, and they were finally torn from Danish control. [=War in Sicily and Sardinia=]