While Germany was in the same state of war and desolation that Hepburn had left it, the great Cardinal-Duke de Richelieu ruled France with a bold and vigorous hand. Feared by one party and secretly hated by another, he held the reins of government in defiance of both, and defeated every conspiracy formed for his overthrow, by making the intrigues of the Duke of Orleans and the queen-mother recoil upon themselves.

In order to render his able services as a minister more necessary to France and his sovereign, he resolved to engage them in a war with Austria—a measure which, before the fall of Gustavus Adolphus, would have produced the most extraordinary events; but being proud, and jealous of the Swedish conqueror, the Cardinal avoided that measure until the power of the Swedes was completely broken by the fatal event at Lutzen, and their defeat at the disastrous battle of Nordlmgen.

That overthrow made him resolve immediately to put Louis XII in possession of Phoipsburg and the fertile province of Alsace, on condition that France should openly join the league against the Emperor; and Louis, though surnamed The Just, acting, as usual, under the influence of favourites, at once entered into the measure.

Jacques Nonpar, the Marshal de la Force, in the spring of 1634 opened the new campaign, which was to carry the limits of France far beyond the frontiers of Picardy and Champagne; while Charles, duke of Lorraine, towards whose territories he was marching, enraged that Louis had lately seized some of his lands, joined the standard of the Emperor with eight hundred horse and two thousand foot, leaving garrisons in all the strong places behind him.

Sir John Hepburn with his Scottish regiment marched on this expedition, before the undertaking of which Bichelieu, who considered his advice on military matters of the highest value, held many conferences with him; and in one of his letters to La Yalette says, "If we could beat Monsieur de Lorraine with the troops that the Marshal de la Force commands in those parts, then we might employ the above-mentioned army in that affair which Colonel Hepburn and I talked about at Compifegne. We expect the return of the Sieur Ferrier, to know whether we must reinforce the Marshal de la Force with horse alone, or horse and foot together.”

Set on restoring the balance of power, which had suffered by the fall of Gustavus, Richelieu formally denounced war against the Empire, and a French herald proclaimed it at the gates of Brussels. The Marshals Coligni de Chatillon and de Maill£ Brege, with twenty-six thousand men, advanced towards the Spanish Netherlands; a second army under the Marshal de Crecqui entered Milan; a third, under the Due de Eohan, occupied the Valteline; a fourth, under the Duke of Saxe-Weimar, moved towards the Rhine; and a fifth, under Jacques de la Force, our Scottish marschal-de-camp, and the far-famed Vicomte de Turenne, unfurled the ori-flamme in the fertile province of Lorraine.

Considering himself as experienced in war, from having commanded in Italy and superintended the siege of Rochelle, the able Richelieu spared no expense in the execution of his vast military projects. Orders were issued, which put the whole of these armies on the best footing for active service; and the excellence of their furniture, artillery, baggage, caissons, and armour, surpassed all that had hitherto been seen in France.

After capturing the small town of Biche, on the Alsatian frontier, with its citadel, which stands on a rock, and was deemed impregnable, they advanced to La Mothe, which they invested early in the month of March 1634, and there Hepburn had soon an opportunity of displaying his skill in besieging. The young Marquis de Toneins, the Vicomte de Turenne, and other nobles who commanded regiments on this expedition, were little more than twenty years of age; and Hepburn, though bearing the baton of a marichal-de-camp, was only six-and-thirty.

This fortified town is situated on the summit of a steep and rocky mountain (the highest ground in the vicinity) and by its cannon swept three neighbouring eminences, as well as the lower approaches. The rocks were impervious to sapping and mining; and at their feet flowed a small stream, which fell into the Maese a little below. Like many others, this town was called impregnable; it had but one gate, over which frowned a row of brass ordnance. It was traversed by one street, and had only one church, the spire of which was rendered a conspicuous object by the loftiness of its situation.

The ancient fortifications were in a form nearly oval, and surrounded the rocks; but the Lorrainers had added several outworks, strengthened by deep fosses and stonefaced ramparts. M. d’Ische commanded the garrison, which was numerous and resolute, as well as the bourgeois, who were all in their armour, and devoted to Charles of Lorraine.

Louis XIII. did not think the possession of this place necessary to render his conquest complete, says the Abbe Augustin Calmet, as it was far off from the usual roads, detached from the body of Lorraine, a place so little and difficult of access that it was alike useless as a place of retreat, or for maintaining a strong garrison of soldiers. Nevertheless, as the Imperialists were still fifty leagues distant, Hepburn and La Force drew round it a line of circumvallation, consisting of a trench and breastwork of earth, for the double purpose of enclosing the town and of preventing its relief by the enemy, should they come up in time. On this line were seven batteries, mounting thirty pieces of cannon; and although an assault was only practicable on one point, they resolved to make four, and dug five mines with the greatest difficulty, because the rock was as hard as adamant.

On the place being summoned, Monsieur d’Ische refused to surrender; and the Marshal having made all his dispositions, and foreseeing that the defence would be protracted, left the Marschal-de-camp with his Scottish regiment, the Marquis de Toneins, and the Vicomtes of Turenne and Arpajou, with their regiments, to continue the siege, while he penetrated with the main body farther into Lorraine.

Hepburn commenced his trenched approaches towards the place, and suffered severely from the incessant cannonading, which tore down the loose parapets, and buried his killed and wounded soldiers, armour, drums, and. eveiy-thing, under vast heaps of earth, interrupting the progress of the works, which were still further retarded by several sorties of the besieged, who in the night frequently fell upon the outguards and workers with clubbed arque-busses and levelled pikes. The gay young Marquis de Toneins, son of La Force, who at the head of his regiment of pikemen had attempted to storm a bastion, was repulsed with great loss; for the fire from the angles of the ramparts swept away his soldiers in scores, and hurled them over the rocks into the water below.

Next day his rival, the Vicomte de Turenne, mounted the trenches with his regiment of infantry, and advanced to assault the same bastion, while, by his rising reputation, Hepburn and the whole army were attentive to his progress. Amid clouds of smoke, a line of mingled fire and steel that flashed from the steep ramparts, the gallant Turenne led on his soldiers, with his visor up, his sword drawn in one hand, and the white banner with the silver lilies in the other. Ever and anon great breaches were made in his ranks by enormous stones, which were hurled from the ramparts, and which, says the Chevalier Ramsay (knight of St Lazarus,) “by falling on the points of the rocks, split into a thousand pieces, killing and wounding all who dared to approach.”

Animated by the brief success of the preceding day, the Lorrainers fought with ardour; but their efforts were vain; and with pleasure Hepburn, from his lines, saw the bright helmets of Turenne’s regiment glitter on the enemy’s works, which they carried and won by dint of sword and pike; and the frequent waving of the white oriflamme announced to the troops below that the Vicomte had effected a lodgment among the outer fortifications.

On the 15th May, Hepburn sent eighty of his Scottish musketeers to one of the three eminences near the town, which, from its position, enabled them to sweep one of the enemy’s works in flank; but they were boldly repulsed by M. d’lsche, the governor, who sent two successive bodies of musketeers to drive them back—a movement the result of which he watched from the ramparts. He also gave permission to as many of the bourgeois as pleased to take part in this action.

Accordingly, all sheathed in body armour, but variously equipped with swords, pikes, arquebusses, (which they fired over rests like a hayfork) partisans and poleaxes, a strong band of townsmen now issued from a postern gate, and, encouraged by their numbers, made a furious attack upon the eighty men of Le Regiment de Hepburn. But the Scottish musketeers kept shoulder to shoulder like a wall of burnished steel, and fired with deadly precision as they retreated slowly with their faces to the enemy. Eighteen of their number being killed and wounded, the rest were obliged to retire as fast as possible, and were pursued by the inflated bourgeois until Hepburn sent a squadron of the gendarmerie, who suddenly filed out of the trenches, fell upon them sword in hand, and, by nearly cutting them entirely off, enabled the Scots to rejoin their regiment.

During these operations M. d’Ische, the governor, was killed by a musket-ball. His son succeeded to the command; but so vigorously had Hepburn pushed the siege, and intercepted all supplies, that by this time the Lorrainers were reduced to the greatest straits, and with despair saw their wives and children famishing around them.

Having skilfully lodged his own regiment in the fosse, at a place where the cannon of the enemy could not molest him, the Marquis de Toneins and other French officers made a similar attempt, but failed to obtain so sheltered a lodgment; and the besieged fired so rapidly, and hurled such showers of bullets, stones, burning brands, and other missiles, that, after enduring them for eight days, they were obliged to draw off their soldiers and retire.

At seven in the morning of the 25th July the besieged perceived a number of ichelles (or scaling-ladders) prepared near Hepburn’s post, at the foot of the battery and des batteries royales, which caused them no small alarm, as a general assault was expected; and eighty musketeers, who had gained the angle of his trench to enfilade any intended attack, were furiously repulsed by the Scots with the loss of many killed.

Further resistance being considered vain, the fortress capitulated on the 28th July, after a siege of nearly five months, during which Hepburn’s regiment lost one captain and a great many soldiers.

In this affair Hepburn and Turenne distinguished themselves so much by their prudence and gallantry that their exertions were considered the chief cause of gaining the place; and the Cardinal de Richelieu gave the latter, though only in his twenty-third year, the commission of marschal-de-camp. This rank was then of the first dignity, next to a Marshal of France, where as yet Lieutenant-Generals were unknown; but it was an elevation which wounded the pride and piqued the jealousy of his military rival, the young Marquis de Toneins, whose petulance evinced itself on several occasions.