Butler then went into Poland, and at his own expense raised a fine regiment of cavalry, all clad in buff coats, with back and breast pieces, and triple-barred helmets. While recruiting there he daily ran the risk of being murdered by the Polish peasantry, who were averse to the Imperial service; but he marched as soon as his new levy was completed, and on his return to the Emperor's army took possession of Prague, the capital of Bohemia. This made him more than ever a favourite of the great Wallenstein.
Soon after this exploit he married the Countess of Fondowna.
He was at Prague when the ambitious Wallenstein became false to the interests of the Empire, and fell into the deadly snare prepared for him at Egra by Colonel James Butler and others, on whose unscrupulous fidelity the Imperial court could rely. Had Walter not been a rigidly honourable man, he might have realized a large fortune by the death of his leader, who, being always fond of foreign troops, wished him to return to Ireland for the purpose of raising a body of infantry to cope with the Scottish brigades of Gustavus. For this purpose he offered him money to the amount of 32,000l. sterling by bills of exchange at Hamburg, and ready cash, which was lying useless at his palace of Sagan, on the bank of the Bober, in Prussian Silesia. But he declined the service with these remarkable words—"Poor old Ireland has been drained too much of her men already." This anecdote, says Walter Harte in his history, I learned at Vienna.
The wild schemes and daring ambition of Wallenstein now made him indulge in the hope of dismembering the great conquests of the Empire, and seating himself upon a new throne, to be erected by the sword in northern Europe. This hope was crushed in 1634, when the great duke was spending the holidays of Christmas in the old castle of Egra in Bohemia. The garrison in this fortress was commanded by John Gordon, a Presbyterian, a native of Aberdeenshire, who was colonel of Tzertzski's regiment, and had once been a private soldier. Wallenstein's personal escort consisted of 250 men of James Butler's Irish regiment, commanded by that officer in person.
James Butler (without communicating the matter to his brother Walter), John Gordon, and Major Walter Lesley, son of the Laird of Balquhan in the Garioch, on receiving private instructions from Vienna, resolved, without scruple or remorse, on removing the ambitious general from the path of the emperor for ever. Butler prepared a grand banquet, to which he invited the generalissimo's attendants. Previous to the latter, Butler, who, felt some distrust of Lesley and Gordon, who were both Scots and Presbyterians, while he was a Catholic, made some remarks expressive of admiration for the duke.
"You may do as you please, gentlemen, in the matter at issue," said Gordon; "but death itself shall never alienate me from the duty and affection I bear his majesty the emperor."
Thus encouraged, Butler produced a letter from Mathias Count Galas (who, after the siege of Mantua, obtained the supreme command of the Imperial army), wherein Ferdinand II. authorized them and all his officers to withdraw "their allegiance" from Wallenstein, for all the troops had taken an oath of obedience to him by the emperor's express order. Fully empowered by this document to do what they pleased, the three mercenaries resolved on his immediate destruction. One proposed to poison him; another suggested that he should be sent a prisoner to Vienna; a third, that he should be slain after disposing of his friends at the banquet. The last was at once adopted, and several were invited, among whom were Wallenstein's brother-in-law, Colonel Tzertzski; Colonels Illo, William Kinski, and the secretary, Colonel Niemann. The castle was filled with soldiers on whom Gordon and Butler could rely. As the fatal evening drew on, Captain Walter Devereaux, Watchmaster Robert Geraldine, and fifteen other Irishmen, entered the keep, and took possession of a postern; while to Captain Edmund Bourke, with one hundred more, was assigned the duty of keeping the streets quiet; for Tzertzski's dragoons occupied the town, which is the capital of its circle, and was then surrounded by a triple rampart, washed on one side by the Egra.
The banquet was protracted so long that at half-past ten the dessert was still on the table, when Colonel Gordon filled up a goblet of wine, and proposed the health of the shy and cunning John George, Elector of Saxony, the enemy of the emperor.
Butler affected astonishment, and said "he would drink to no man's prosperity who was the enemy of Cæsar."
Pretended high words ensued, and while the unsuspecting friends of Wallenstein gazed about them in wonder and perplexity, the doors were flung open, and Geraldine and Devereaux, with their soldiers armed with drawn swords or partizans, rushed in.