In the beginning of June, the king of Prussia, understanding that the Russian army had begun their march from the Vistula, ordered the several bodies of his troops, under Hulsen and Wobersnow, reinforced by detachments from his other armies, to join the forces under count Dohna, as general in chief, and march into Poland. Accordingly, they advanced to Meritz, where the count having published a declaration 523 [See note 4 D, at the end of this Vol.], he continued his march towards Posna, where he found the Russian army, under count Soltikoff, strongly encamped, having in their rear that city and the river Warta, and in their front a formidable intrenchment mounted with a great number of cannon.
Count Dohna, judging it impracticable to attack them in this situation with any prospect of success, endeavoured to intercept their convoys to the eastward; but for want of provisions, was in a little time obliged to return towards the Oder: then the Russians advanced to Zullichaw, in Silesia. The king of Prussia thinking count Dohna had been rather too cautious, considering the emergency of his affairs, gave him leave to retire for the benefit of his health, and conferred his command upon general Wedel, who resolved to give the Russians battle without delay. Thus determined, he marched against them in two columns, and on the twenty-third day of July attacked them at Kay, near Zullichaw, where, after a very obstinate engagement, he was repulsed with great loss, Wobersnow being killed and Manteuffel wounded in the action; and in a few days the Russians made themselves masters of Franckfort upon the Oder.
By this time the armies of count Daun and the king of Prussia had made several motions. The Austrians having quitted their camp at Schurtz, advanced towards Zittau in Lusatia, where having halted a few days, they resumed their march, and encamped at Gorlithayn, between Sudenberg and Mark-Dissau. His Prussian majesty, in order to observe their motions, marched by the way of Hertzberg to Lahn, and his vanguard skirmished with that of the Austrians, commanded by Laudohn, who entered Silesia by the way of Griffenberg. The Austrian general was obliged to retreat with loss; while the king penetrated into Silesia, that he might be at hand to act against the Russians, whose progress was now become the chief object of his apprehension. He no sooner received intimation that Wedel had been worsted, than he marched with a select body of ten thousand men from his camp in Silesia, in order to take upon him the command of Wedel’s army, leaving the rest of his forces strongly encamped, under the direction of his brother prince Henry, who had joined him before this event. Count Daun being apprized of the king’s intention, and knowing the Russians were very defective in cavalry, immediately detached a body of twelve thousand horse to join them, under the command of Laudohn, and these, penetrating in two columns through Silesia and Lusatia, with some loss, arrived in the Russian camp at a very critical juncture. Meanwhile the king of Prussia joined general Wedel on the fourth day of August, at Muhlrose, where he assumed the command of the army; but finding it greatly inferior to the enemy, he recalled general Finck, whom he had detached some time before, with a body of nine thousand men, to oppose the progress of the imperialists in Saxony; for when prince Henry joined his brother in Silesia, the army of the empire had entered that electorate. Thus reinforced, the number of the king’s army at Muhlrose did not exceed fifty thousand, whereas the Russians were more numerous by thirty thousand. They had chosen a strong camp at the village of Cunersdorf, almost opposite to Franckfort upon the Oder, and increased the natural strength of their situation, by intrenchments mounted with a numerous artillery. In other circumstances it might have been deemed a rash and ridiculous enterprise, to attack such an army under such complicated disadvantages; but here was no room for hesitation. The king’s affairs seemed to require a desperate effort, and perhaps he was partly impelled by self-confidence and animosity.