From Donauworth he marched to Nuremberg, stayed there forty-eight hours to recover the fortress of Lauf, and, having forced the garrison of that place to surrender at discretion, pushed on with all possible speed to Erfurt, which he had fixed upon as the point of junction for his several corps.  The Green Brigade formed a portion of the force which Gustavus left behind him in Bavaria under the Prince Palatine.  So terribly weakened were the Scottish regiments by the various battles of the campaign, in all of which they had borne the brunt of the fighting, that Gustavus determined reluctantly to leave them behind for rest and reorganization.

Hepburn, Sir James Hamilton, Sir James Ramsay, and the Marquis of Hamilton, who like Hepburn had quarrelled with Gustavus, left the Swedish army the day after they arrived at Neustadt, after marching away from Nuremberg.  All the Scottish officers in the Swedish army accompanied Hepburn and his three companions along the road for a long German mile from Neustadt, and then parted with great grief from the gallant cavalier who had led them so often to victory.

Malcolm Graheme did not remain behind in Bavaria with his comrades of the Green Brigade.  Gustavus, who had taken a great fancy to the young Scotch officer, whose spirit of adventure and daring were in strong harmony with his own character, appointed him to ride on his own personal staff.  Although he parted with regret from his comrades, Malcolm was glad to accompany the king on his northward march, for there was no probability of any very active service in Bavaria, and it was certain that a desperate battle would be fought when Gustavus and Wallenstein met face to face in the open field.

At Erfurt Gustavus was joined by Duke Bernhard of Saxe-Weimar with his force, which raised his army to a strength of 20,000.  The news of his approach had again revived the courage of the Elector of Saxony, who had occupied the only towns where the Elbe could be crossed, Dresden, Torgau, and Wittenberg —­ he himself, with his main army of 15,000 men, lying at Torgau.  From him Gustavus learned that the Imperial army was divided into three chief corps —­ that of Wallenstein 12,000 strong, that of Pappenheim 10,000, those of Gallas and Holk united 16,000, making a total of 38,000 men.

So great was the speed with which Gustavus had marched to Erfurt that Wallenstein had received no notice of his approach; and believing that for some time to come he should meet with no serious opposition, he had on the very day after the Swedes reached Erfurt despatched Gallas with 12,000 men into Bohemia.  A division of his troops was at the same time threatening Naumburg, whose possession would enable him to block the only easy road with which Gustavus could enter the country held by him.