[Sidenote: § 3. The Congress at Brussels.]
In the meantime the diplomatists had met at Brussels. After some difficulties of form had been got over, Sir Richard Weston, the representative of England, sent to ask Frederick to agree to a truce. When the message reached him the battle of Wimpfen had not been fought, and his hopes were still high. A truce, he wrote to his father-in-law, would be his utter ruin. The country was exhausted. Unless his army lived by plunder it could not exist. A few days later he was a beaten man. On May 13 he gave way, and promised to agree to the truce. On the 28th all was again changed. He had learned that the Margrave of Baden hoped to bring back his army into the field. He knew that Christian of Brunswick was approaching from beyond the Main; and he informed Weston that he could do nothing to assist the negotiations at Brussels.
[Sidenote: § 4. Seizure of the Landgrave of Darmstadt.]
On June 1 Frederick and Mansfeld marched out of Mannheim to meet Christian. On their way they passed by Darmstadt. The Landgrave was especially obnoxious to them, as a Lutheran prince who had warmly adopted the Emperor's side. Love of peace, combined with pretensions to lands in dispute with the Landgrave of Hesse Cassel, in which he hoped to be supported by Ferdinand, had made him a bitter enemy of Mansfeld and his proceedings; and though it was not known at the time that he was actually in receipt of a Spanish pension, Frederick was not likely to attribute to other than interested motives a line of action which seemed so incomprehensible.
[Sidenote: § 5. Mansfeld unable to pass the Main.]
As soon as the troops reached Darmstadt, they commenced their usual work, ravaging the country, and driving off the cattle. To the Landgrave, who recommended submission to the Emperor as the best way of recovering peace, Frederick used high language. It was not in quest of peace that he had come so far. The Landgrave had a fortified post which commanded a passage over the Main, and its possession would enable the army to join Christian without difficulty. But the Landgrave was firm; and finding that a denial would not be taken, tried to avoid his importunate guests by flight. He was overtaken and brought back a prisoner. But even in this plight he would give no orders for the surrender of the post, and its commander resolutely refused to give it up without instructions. Before another passage could be found, Tilly had received reinforcements, and Frederick, carrying the Landgrave with him, was driven to retreat to Mannheim, not without loss.