Brown afterwards adopted the general's opinion, that a night attack was best; and the time and manner he proposed met with the consent of all who were present at their conference.
Selecting 6000 men, he chose the 10th of August for this desperate expedition; and Lobcowitz, to conceal all knowledge of the route chosen by the count in attacking Viletri, threw a chain of picquets and videttes over a vast extent of country. In silence, and without the sound of drum or bugle, he marched from the camp; and none of his troops, save the Marquis de Novati, his second in command, were informed of the object until they reached a valley at the foot of the mountain, near a church dedicated to St. Mary. The darkness of the night (says Castruccio Buonamici) was rendered more dense by the shade of the overhanging vines.
At this moment, during a temporary halt, it was reported to the count that a soldier had deserted, and perhaps to the enemy. The Marquis de Novati fearing they were betrayed, urged a retreat, but Brown exclaimed:—
"No; I am determined to advance. The die of war has been thrown!"
And promising his soldiers ample rewards, he exhorted them to behave like brave men. Pushing on with ardour, the attack was commenced just as day began to break, by the cavalry outposts being cut to pieces, and the left flank of Viletri being furiously assailed, the infantry pushing on through walls and vineyards, and the Hungarian horsemen with lance and sabre hewing a passage to the streets. A regiment of Italian dragoons were put to flight. The brave Irish Brigade attacked the advancing Austrians with such fury, as to hold them in check for half-an-hour, but in the end were nearly cut to pieces at the Neapolitan Gate. Marsiglia of Sienna, a Knight of Malta, defended a cottage with fifty dismounted dragoons, and displayed incredible bravery. The Walloon Guards were unable to assist the Irish until they were nearly all slain. Colonel Macdonel, eleven captains, thirty subalterns, and a heap of Irish dead, blocked up the gate they had defended. The fury, the firing, and the slaughter on all sides of the hill were frightful. The King of Naples put himself at the head of his guards, crying, "Remember your king and your ancient valour." But his efforts were vain; the gates were all forced, his troops driven out, and nine of their standards taken. The street which led to the Ginnetti palace was set in flames; the Duke of Atri was nearly burned alive, and General Count Mariano was captured in bed. Brown's second in command, the Marquis de Novati, was taken prisoner, and finding his troops, who were busy plundering, about to be surrounded by those of Count Gages, he ordered his drums to beat a retreat, and retired to the intrenched camp of Lobcowitz. In this expedition he killed and captured 3000 men, hamstrung 800 horses, and brought off 500 more laden with plunder; one general, one hundred other officers, twelve standards, and three small colours. His own loss was only 500.
Disheartened by the partial failure of this affair—for the King of Naples had escaped them—destitute of forage for their cavalry and artillery, and encumbered with many sick and wounded men, Lobcowitz and Brown finding themselves unable to hazard a general engagement, and that autumn was at hand, became desirous of retreating; and after pillaging Valmonte and cutting the Duke of Portocarrara's Italian corps to pieces, transporting their baggage and sick by sea to Tuscany, they threw a pontoon bridge across the Tiber beside the Ponte Molle, and commenced a retreat in the night, demolishing all bridges as they left them behind, to bar pursuit.
The count was named "the right hand" of Lobcowitz during the arduous operations which ensued; and, by his usual activity and bravery, he frequently repulsed the pursuing Spaniards on the retreat from Viletri, during the fortification of the Austrian camp at Viterbo, the retreat from thence through the forests of Orvietto, with a force now diminished to 13,000 men; the assault upon Nocera, where Count Soro and 900 Italian deserters fell into the hands of Count Gages, who sent them in chains to San Giovanni, where every fifth man was shot—and many other similar affairs, until the Imperialists reached their winter quarters at Rimini, Cesano, and Forli, on which the Spaniards and Neapolitans retired to Pesero and Fano.
In the beginning of the following year, 1745, he was recalled from Italy by Maria Theresa, and sent into Bavaria at the head of a body of troops against the young Elector, who was in alliance with France. He took the town of Vilshosen by assault, and captured 3600 prisoners: 2000 were slain on both sides, and 6000 Hessians were forced to lay down their arms, and enter the British service for the campaign against the unfortunate Prince Charles Stuart. The count would have performed many other feats of equal brilliance, had the war against Bavaria not been terminated suddenly by the terrified Elector, who, at the same time that Vilshosen was taken, lost Pfarrkirchen, Landshut, and had all his magazines destroyed, which compelled him to sign the treaty of Fussen, and in April to conclude a peace with the Empress-Queen. In the same year Count Brown was appointed General of the Austrian Ordnance.
Though peace had been made with the Bavarian Elector, there was no rest for the soldier of fortune, who was immediately dispatched a third time to Italy, with 18,000 men, against the Spaniards, by Maria Theresa, whose husband had now been elected Emperor of Germany. He joined the Prince of Lichenstein, who was carrying on the war against the still-allied French and Spaniards under the Marshal de Maillebois; and one of his first essays in the new Italian campaign was to attempt the recovery of the Milanese, out of which, solely by his activity, the allies were ultimately driven.
He also formed a daring scheme to cut off the communication between the main body of the Spanish army and their forces under the Marquis de Castellar, by detaching General Nadasti along the left bank of the Po, with orders to amuse the enemy by countermarches, and by pretending to lay a pontoon bridge across the river at Casale-maggiore, a town in Lombardy. While the deceived Spaniards were busy watching these feigned motions, their guards, who occupied the right bank of the Po, were surprised and utterly cut to pieces by the Austrian irregulars; and then Count Brown crossed the river at Borgoforte, near the strong Venetian castle, and pushing on from thence, captured Luzzara, a Parmese town four miles north of the scene of his services twelve years before—Guastalla, which he immediately invested, and took by assault, when Marshal Count Corasin surrendered, with 2000 prisoners. At this very time Castellar, with 7000 Spaniards, hovered on one flank of the count's little force, and Gages was advancing on the other; two movements by which his division must have been overwhelmed, had not the Prince of Lichenstein advanced to his support; and on uniting they took Parma.