In 1625 Gustavus Adolphus having renewed hostilities with Sigismund, King of Poland, who had ever treated him with undisguised insult, and even taunted him as a usurper, Colonel Hepburn’s Scottish regiment formed part of the army which invaded Polish Prussia, and served in that victorious campaign which gave Selburg, Nidorp, Dorpat, and Duneberg to Gustavus, and ended in the total rout of the Polish army on the plains of Semigallia, in the duchy of Courland.

It was during this Polish war that Hepburn began the series of brilliant achievements which marked his career under the banner of Gustavus; for the love of bold adventure and military display, which had led him from his father’s quiet home in the pastoral district of Dirleton, found an ample field in the operations of the armies on the banks of the Versa and the Vistula.

Gustavus having resolved to effect the relief of Mewe, a town of Western Prussia, where his garrison was closely blocked up, despatched upon this duty two officers, who, though young in years, were old in experience— "the Count Thurm, and Colonel Hepburn, a Scottish officer of great ability and approved courage, who conducted the attack.”

This town, which is strongly situated on the confluence of the Versa with the Vistula, and has its walls washed by both these rivers, was blockaded by King Sigismund at the head of thirty thousand Poles, whom he had intrenched on a steep green eminence, cutting off all communication between the town and the surrounding country. By this eminence he foresaw that the Swedes must pass, if they made any attempt to raise the siege. He strengthened it by the erection of two batteries of heavy cannon, which commanded the approach by a cross fire; while the whole line of his intrenched infantry, with their bows and matchlocks, swept the ground which descended abruptly from their earthen parapets.

As it was absolutely necessary for the success of the campaign that this blockade should be broken and the town relieved, the able Gustavus examined the ground long and attentively; for on the possession of this place depended his hopes of gaining Dantzic, and terminating the war victoriously.

He selected in his camp at Dirschau three thousand chosen Scottish infantry, among whom were Hepburn’s own regiment, and five hundred horse under Count Thurm, to all of whom he delivered a short address on the desperate duty they were about to attempt—to cut a passage over a fortified hill defended by thirty thousand men.

Hepburn marched the column from the Swedish trenches, and without sound of drum or trumpet, as he intended in the dusk to proceed by a secret path, and turn the Polish flanks; for in every essay of arms Hepburn proved eminently, what a celebrated French writer has affirmed, that war, though a trade for the ignorant, is a science for men of genius. Dirschau is situated upon the Wezel or Vistula, and a march of a few hours brought Hepburn in view of the height on which the Polish infantry, clad in mail of a half Oriental fashion, and armed with muskets, bows, and matchlocks, iron maces, lances, scimitars and targets, were strongly intrenched—with their brass cannon bristling through the green brushwood on their right and left. In their rear lay the spires of Mewe.

Night was coming on, and finding his approach was as yet unseen, Hepburn made a flank movement, and began to ascend the hill by a narrow and winding path, encumbered by rocks and stones, thick underwood, and overhanging trees, through which the soldiers, retarded by their heavy muskets and collars of bandoliers, their corslets, helmets and knapsacks, threaded their way with difficulty; for the mountain-side was so steep that they were compelled to grasp the branches in clambering from rock to rock, so that a historian has likened them to sailors climbing the shrouds of a ship. Hepburn guided them with admirable caution and intrepidity past the advanced posts of the enemy. The side of the wooded mountain was still as death, not a sound being heard but the hoarse roar of the foam-covered Vistula, which, far down below, came rolling from the mountains of Silesia.

In the clear twilight of the northern evening the Scots gained the summit, and the white plume in Hepburn’s helmet was their guide, as they fell furiously with clubbed muskets on the Poles, who were still working busily at their trenches, which were stormed at push of pike. A deadly fire of musketry, mingled with showers of arrows, stones, and other missiles, opening on the Scots from various points, compelled them to recoil; and then dense hordes of mounted Cossacks and Heyducks, clad in mail shirts and steel caps, pressed at full speed, with their long lances and sharp scimitars, on the retiring column. Hepburn drew off his men to a rock that was defensible, charged again and again by these wild light horsemen, who exultingly shouted, "These curs abide not the bite of the Polish wolves!”

"Immovable as a wall of brass, the brave Scottish pikemen stood shoulder to shoulder;” while before them was placed another insurmountable obstacle, the portable chevaux-de-frise, which they fixed along their front—the ptla suilla of the historian Loccenius, and the u Swedish feathers of the famous Captain Dugald Dalgetty.

On this rock, where he was joined by Colonel Mostyn, an Englishman, and Count Brahe with two hundred German arquebusiers, Hepburn defended himself for two whole days against the entire force of the Polish army, led by the young Prince Udislaus, whose father, the king, happened on this occasion to be absent from the camp. Daring these two days of incessant fighting, Gustavus achieved the relief of the town, by putting into it a supply of men and ammunition; upon which the Poles abandoned their trenches and retired. It was computed that each of Hepburn’s soldiers killed a man, and yet lost only one-seventh of their own number.

Gustavus permitted the Poles to retire without pursuit; for it was a maxim with the generals of those days not to follow such troops too hastily, as they made war in an irregular and desultoxy manner.

In 1626 the Scots fought well in the neighbourhood of Dantzic, under Lieutenant-General Sir Alexander Leslie of Balgonie, (afterwards first Earl of Leven,) an old veteran of the Dutch and Bohemian wars.

That famous leader, with Colonel Dideraik Sperreti-ter, having been sent with two Scottish companies and a troop of dragoons to reconnoitre the camp of King Sigismund, they were suddenly surrounded by seventeen troops of fierce Polish cavalry near the village of Girlinerwals, and a deadly strife ensued; for the Poles were savage by nature, and the Scots had engendered sentiments of hostility against them in consequence of a book abusive of the nation having been written by a Pole named Stircovius, whom James VI. had caused to be hanged in 1613. A minute of council is still preserved, which contains the expenses incurred by Patrick Gordon for apprehending “Stircovius, who writt and set out the infamous booke.”

The spearmen of Leslie broke through the dense masses of horsemen twice, and after cutting a hundred men to pieces, and capturing four troop-standards, retired with little loss. This brought on a general engagement, for the whole Polish army advanced in line to support their cavalry, but were defeated by Gustavus with the loss of three thousand men, four field-pieces, and fourteen standards.