The King went over to Germany soon after; Lord Reay accompanied him with the available half of the regiment; Monro was sent to East Prussia to take over the independent command of his companies there, with orders to rejoin the King with them as soon as possible. He presented himself to the "Rex-Chancellor", who was installed as Governor of that province, and a few months after the opening of the campaign was ready to embark his men at Pillau, whence they steered for Wolgast in Pomerania.

He reached the Pomeranian coast in a heavy storm, which caused the ship to spring a leak, and finally piled it up on a sandbank, whence Monro with great difficulty made his way ashore; his arms and men were indeed retrieved, but all his baggage and ammunition was lost, and in this condition he found himself isolated on the coast, twenty German miles east of Stettin (where the King was) and with enemies ensconced everywhere in the surrounding country. He succeeded, nevertheless, in extricating himself adroitly from his precarious position, and made contact with the main army; and despite the crossness of fate he essays on this occasion a short lyrical flight:

"Having thus by the providence of God happily landed againe on the faire, fertill, and spacious Continent of Dutchland, with a handfull of old experimented Soldiers, able to endure all misery, toile, or travell, being valourous to undertake any peril or danger, they were to be commanded upon, being led by such a Generall as GUSTAVUS the Invincible, their new Master was: (under whose command and conduct, as their supreame Leader, and me, as his Majesties and my Colonels inferiour Officer, they marched from the Coast of Pomerne, out of Rougenvalde, through Dutchland, unto the foot of the Alpes in Schwabland . . .")

Alas!, he sighs upon a later occasion, had but our master not been taken from us, "the King of Captains and the Captain of Kings", we should have crossed the Alps at that time, and paid Rome a visit.

From the moment when Monro enters upon his long march through Germany in company with the King’s army — to which he and his regiment continued to be attached almost until the battle of Lützen — his tone is pitched higher than before, and his attitude to the trade of war undergoes a certain transformation. During the Danish campaigns it is his regiment, its weal or woe, its battle honours, which is all in all to him: the army as a whole scarcely exists for him, so little does he feel himself to be a part of it; and in enterprises common to them all he takes but little interest. When he writes "we", he invariably means simply "the regiment". But under Gustavus Adolphus he at once sees the operations as a whole, feels a strong esprit de corps: when now he writes "we", he means the whole army. Naturally he continues to use every suitable opportunity to vent his purely Scottish sentiments; but they do not now stand in the way of his corporate loyalty: the King may certainly be proud to possess such a regiment as Monro’s, but on the other hand Monro takes unbounded pride in serving such a King — of never dying memory. .. Illustrissimu: among Generalls... the Phoenix of his time. The exploits of the Scots of course claim the greater part of his space, for he narrates only what he personally has witnessed; but he freely admits that others than the Scots can distinguish themselves: the German foot, particularly those of the blue and yellow brigade, are not the men to be daunted by bagatelles; the Swedes too bear themselves worthily in the open field and in attacks on fortified positions; and the Finns, whom he calls Haggapells, are useful men on horseback, valuable in dangerous enterprises, and well able to meet the curiassiers of Holck and Montecucculi on level terms.

Within his own branch of the military art Monro has very definite views on the differing value of musketeers and pikemen, which together composed, in almost equal proportions, the infantry of that age. Musketeers, he considers, are no doubt serviceable in many ways, especially to send forward ahead of the army as skirmishers; the new Swedish system of interspersing the cavalry with musketeer platoons is also highly to be recommended. But when there is really serious work to be done, the musketeers reveal their limitations: in large-scale frontal attacks on fortified towns, in particular, they show a lack of sense of duty and a certain insecurity in morale, which sometimes it is impossible wholly to counteract; they have an ingrained tendency to scatter in search of plunder as soon as they have got inside the ramparts, leaving standards and officers to take care of themselves; while pikemen have better self-control. And in general Monro holds the view that the pike is a far nobler weapon than the musket:

"Pike-men being resolute men, shall be ever my choyce in going on execution, as also in retiring honourably with disadvantage from an enemy, especially against horsemen: and we see offtimes,. . that when musketiers doe disbandon, of greedinesse to make booty, the worthy pike-men remaine standing firme with their Officers, guarding them and their Colours, as being worthy the glorious name of brave Souldiers, preferring vertue before the love of gold, that vanisheth while vertue remaineth. . .The Pike {is] the most honourable of all weapons, and my choise in day of battell, and leaping a storme or entering a breach with a light brestplate and a good head-piece, being seconded with good fellows, I would chose a good halfe-Pike to enter with."

In mid-winter the King broke up from Stettin with a portion of his army, and moved forward in snow-storms and severe cold to Neu-Brandenburg, which was easily taken. According to Monro, the officers and men who composed its garrison were, in a military point of view, the most wretched collection he had ever set eyes on; but (he adds) that was no more than was to be expected, since they consisted exclusively of poor simple Italians, who could hardly be expected to have much idea of warfare. Nevertheless the garrison duties of this battered troop had left ample leisure for plundering the surrounding country; and hence the leading elements of the King’s troops came upon considerable quantities of money and gold chains. Despite the feeble resistance Monro had been profoundly impressed by the whole operation, and here breaks into a long dithyramb on the King’s unique endowments as a commander. "Such a Master would I gladlie serve; but such a Master," he adds sadly, "I shall hardly see againe." Knyphausen was now put in command of the place; he was in Monro’s view a man well experienced in the science of war, and in his company a cavalier with his wits about him could pick up many a useful lesson, for all that he did not love Scots. It was Knyphausen who formulated the dictum that in war an ounce of luck is worth a pound of calculation; but he was himself invariably unlucky, and not least at Neu-Brandenburg. That half of Lord Reay’s regiment which had come over from Sweden was installed as garrison, after which the King turned his attention elsewhere. Shortly afterwards Tilly appeared before the town and took steps to make himself master of it; Knyphausen delayed too long in treating, and in the final storm almost the entire garrison was put to the sword: only the commandant himself and a number of officers were spared. This was a hard blow for Monro, who here lost many old comrades-in-arms; but he had not long to wait before taking his share in the great revenge at Frankfurt.

The storming of Frankfurt on the Oder, on 3 April 1631, is the most successful piece of narrative in the whole book: it was an event in which Monro personally played an important part. His regiment, or half-regiment, formed — now that the King had finally settled the composition of his tactical unit — together with three other regiments, "the Scotch Brigade", under the command of John Hepburn, a chivalrous and valiant gentleman, and a boyhood friend of Monro. Besides the Scotch Brigade, there were present in this action the Blue and Yellow Brigades; and with the cavalry the King had 10,000 men outside the walls; while inside them Field-Marshal Tiefenbach with 9000 men awaited the onslaught with the utmost composure. Monro here inserts a long strategical discussion on the extreme daring of the enterprise, with Tilly encamped at no great distance, strong in numbers and no less so in the terror inspired by his success at Neu-Brandenburg; and expatiates on the extraordinary nicety of the King’s calculations and general dispositions. Since there was no time for a regular siege, either Tiefenbach must be lured into the open, or the town must be stormed without delay; but neither of these possibilities appeared immediately practicable. After the advancing Swedish army had approached within one German mile of the town, it was drawn up in battle-order by the King in person, and then in all its splendour — the memory of which seems to have been particularly vivid when Monro wrote his book — advanced to offer battle with martial pomp and ceremony. But Tiefenbach was not to be drawn, and the infantry was therefore sent forward to take up suitable positions for a storm. The Scotch Brigade was to attack one of the main gates of the town. It was required to cross a moat, climb an earth rampart furnished with palisades, traverse the space between this and the town wall, and then, if all went well, force its way into the town itself on the heels of the retreating foe. The operation was under the command of Banér. When after a day or two all preparations were complete, the artillery gave the signal for the assault by firing a general salvo, and the Brigades, veiled in smoke, began to advance upon their objective. The Blue and Yellow Brigade, "being esteemed of all the Army both resolute and couragious in all their exploits", came up against Walter Butler’s Irish, and were twice beaten back with great fury and severe losses; it was not until the greater part of Butler’s men had been hewn down and he himself taken prisoner, with a pike wound through the body, that they succeeded in mastering the resistance of these energetic sons of Erin; "and truely," declares Monro, "had all the rest stood so well to it, as the Irish did, we had returned with great losse, and without victory." On his own section of the front they made shorter work of a less heroic resistance, and the Scots quickly found themselves immediately before the gates; but here the enemy resolutely barred the way, supported by a couple of small cannons placed there, and by "flake of small shot, that shot a dozen of shot at once" — clearly some sort of contemporary machine-gun or multiple-barrelled weapon. Monro was the first to enter this somewhat uninviting thoroughfare: the valorous Hepburne, leading on the battaile of pikes, of his owne Briggad, being advanced within halfe a pikes length to the doore, at the entry he was shot above the knee, that he was lame of before, which dazling his senses with great paine forced him to retire, who said to me, bully Monro, I am shot, whereat I was wondrous sorry, his Major then, a resolute Cavalier, advancing to enter was shot dead before the doore, whereupon the Pikes falling backe and standing still, Generall Banier being by, and exhorting all Cavaliers to enter, Colonell Lumsdell and I, being both alike on the head of our owne Colours, he having a Partizan in his hand, and I a halfe Pike, with a head-piece, that covered my head, commanding our Pikes to advance we lead on shoulder to shoulder, Colonell Lumsdell and I fortunately without hurt, enter the Port, where at our entry some I know received their rest, and the enemy forced to retire in confusion, being astonished at our entry, they had neither wit nor courage, as to let downe the Portecullis of the great Port behinde them, so that we entering the streets at their heeles, we made a stand till the body of our Pikes were drawne up orderly, and flancked with Musketiers, and then wee advanced our Pikes charged, and our Musketiers giving fire on the flancks, till the enemy was put in disorder. After us entered Generall Banier, with a fresh body of Musketiers, he followed the enemy in one street, and Lumsdell and I in another, having rancountred the enemy againe, they being well beaten, our Officers tooke nine colours of theirs, which were to be presented to his Majestie, and the most part of the Souldiers were cut off, in revenge of their crueltie used at New Brandenburg, but some of their Officers got quarters, such as they had given to ours."

However, even this glorious day proved no unmixed pleasure for Monro; for the streets were choked, not only with corpses, but with the baggage of the Imperialists — lines of carts and supply-waggons, where a man might pick up "silver services, jewels, gold, money, and clothing". It was too much for the soldiery to resist, especially as they had had the King’s own word for it that a good time was coming. The ranks around Monro quickly thinned, as men slipped off upon their own private concerns; officers were no longer obeyed; by way of increasing the festive spirit, or in order to obtain more light for ransacking the darker recesses, the excited troops set the town alight in various places; some of their own standards were lost in the confusion, and could not be found until next morning, and in some regiments not a man remained with the colours —all of which is gravely deplored by Monro, who frankly admits that on that evening his men were utterly out of hand.

When towards evening the King rode into the town with the Rhine-grave’s cavalry, he appears to have felt no more than modified rapture at what he saw there; he issued a number of stringent orders, but since there were relatively few men within earshot, it took some time before they produced any perceptible effect. A few days later, after the taking of Landsberg, which had proceeded in a more orderly fashion, he had recovered his good humour, and "on the Sabbath day in the afternoone suffered the principall Officers of his Armie (such as Generall Blanier, and Lievetenant Generall Bawtis, and divers others) to make merry, though his Majestic did drinke none himselfe; for his custome was never to drinke much, but very seldome, and upon very rare considerations, where he had some other plot to effectuate, that concerned his advancement, and the weale of his State."

It is of course no accident that Banér and Baudissin are mentioned in connection with this carouse: they were both mighty men with the bottle. The Scots too had famous performers in this way: Major-General Patrick Ruthven, called Pater Rotwein, who in spite of the sternest competition quickly secured for himself an acknowledged pre-eminence as a tippler: he had a head of iron, and could take incredible quantities. He and Baudissin (who was pretty near on the same level) often drank together; but after the King’s death Baudissin took his discharge and entered the Saxon service, presumably attracted by the reputation of the electoral cellars. The two boon-companions were to meet once again: during one of Banér’s earlier campaigns, when each was in command of an independent corps, (though now on opposite sides), they met early one morning in a very odd battle near Domitz; and here Ruthven, being a shade the soberer of the two, seized the opportunity to add one last brilliant victory — though this time of a rather different sort — to his earlier triumphs over Baudissin. Monro, for his part, lingers with pleasure over the companionable carouses he enjoyed when he lay quartered next to Axel Lillie, at Treptow in the Mark of Brandenburg.

"a Towne.. . renowned of old, for brewing of good beere, which during our residence there with the Swedes, we did merrily try, till that we had both quarrelling and swaggering amongst our selves, who before our departure againe were made good friends, reserving our enmity, till we saw our common enemy."

Axel Lillie’s friendship with Monro seems to have stood the test; for six months later, before Mainz, he was sitting in Monro’s redoubt — he had dropped in for a pipe and a chat — when a cannon-ball came and took off his leg.

Immediately after the capture of Frankfurt Monro was given a taste of the King’s hot temper, when he was detailed to put in order a redoubt outside Landsberg, and despite unremitting labour throughout the night did not succeded in having it ready for the King’s early morning inspection. The King took him severely to task, and would hear of no explanations or excuses; but when later on he understood all the circumstances, he was sorry for his hard words. Monro shows no resentment; on the contrary, he thinks all the better of the King for his impatience, which, he says, always caused him to press on the work on field-fortifications to the utmost of his power. And at the same time he concedes that in the matter of digging the German soldiers are handier than the Scots: this is the only instance in which he concedes a superiority to any other nation. And indeed it is one of the King’s most notable qualities as a commander, that he can induce his men, even the mercenaries, to wield the spade without wages:

"Likewise his Majestie was to be commanded for his diligence by night and by day, in setting forwards his workes; for he was ever out of patience, till once they were done, that he might see his Souldiers secured and guarded from their enemies; for when he was weakest, he digged most in the ground; for in one yeare what at Swede, Francford, Landsberg, Brandenburg, Verbum, Tannermoñde, Wittenberg, and Wirtzburg, he caused his Souldiers to worke more for nothing, than the States of Holland could get wrought in three yeares, though they should bestow every yeare a Tunne of gold: and this he did not onely to secure his Souldiers from the enemy, but also to keepe them from idlenesse."

After sundry less colourful episodes from the campaign in Brandenburg and the march to Berlin, Monro’s simple epic winds deviously on to the camp at Werben — a camp of a type which was invented by Gustavus Adolphus, and was considered by contemporaries as a miracle of fieldfortification. Werben not only confirmed Monro in his enthusiasm for the King’s military genius, but afforded him a proof of his singular good fortune in everything he undertook, so that he might indeed fitly he called Mars his Minion and Fortunes Favourite. For in Brandenburg the plague had raged so hot, that Monro lost thirty men of his regiment in a single week; while in Werben, only six day’s march away, every trace of it vanished at once from the whole army, which could not be considered otherwise than as a miracle from God. Tilly showed himself before the camp, with a view to trying an assault; but he was much harassed by anxiety for his food-supply, since the King’s cavalry had swept the country clear beforehand, and after considering the matter for a day or two he sullenly retired. The Swedes soon broke camp to follow him; and passing the Elbe at Wittenberg, there made their junction with the army of the Elector of Saxony. The Saxon army, when they first met it drawn up in parade-order, looked brand-new, and glittered amazingly, while the King’s men looked worn and tattered; "nevertheless," says Monro, "we thought not the worse of our selves." And now at last they were ready, as he puts it, to advance "conjunctis viribius" against the champion of the House of Austria and the Catholic League; and the united armies set themselves in motion towards Breitenfeld.

"As the Larke begunne to peepe, the seventh of September 1631" the drums of the Swedish army beat to arms; and after the men had fortified their bodies with victuals, and their souls with meditation and the confession of their sins, they covered — not without some difficulty — the last piece of the way to Tilly’s positions. By noon the armies were ranged front to front, and the exchange of cannonading could begin; this was sufficiently trying for the foot, who during a wait of some hours had nothing to do but to stand still and fill the gaps in their ranks; "the sound of such musick being scarce worth the hearing, though martiall I confesse, yet, if you can have so much patience, with farre lesse danger, to reade this dutie to an end, you shall finde the musicke well paide; but with such Coyne, that the players would not stay for a world to receive the last of it, being over-joyed in their flying."

The Scottish Brigade was placed in the second line, but after the armies came to grips had the good luck to get a better chance to distinguish itself than the Brigades further forward, which were never engaged at all. For when Tilly, after crushing the Saxons, sent the mass of his infantry crashing into Horn’s wing, it was the Scots, among others, whom the King himself sent forward to check them. And Monro has succeeded in capturing a sort of smoke-swept impression, of the obscurity and confusion of a seventeenth-century battlefield, in his description of the moment when his men came to grips with Tilly’s tercios:

"The enemies Battaile standing firme, looking on us at a neere distance, and seeing the other Briggads and ours wheeleing about, making front unto them, they were prepared with a firme resolution to receive us with a salve of Cannon and Muskets; but our small Ordinance being twice discharged amongst them, and before we stirred, we charged them with a salve of muskets, which was repaied, and incontinent our Brigged advancing unto them with push of pike, putting one of their battailes in disorder, fell on the execution, so that they were put to the route.

I having commanded the right wing of our musketiers, being my Lord of Rhees and Lumsdells, we advanced on the other body of the enemies, which defended their Cannon, and beating them from their Cannon, we were master of their Cannon, and consequently of the field, but the smoake being great, the dust being raised, we were as in a dark cloude, not seeing the halfe of our actions, much lesse discerning, either the way of our enemies, or yet the rest of our Briggads: whereupon, having a drummer by me, I caused him beate the Scots march, till it clered up, which recollected our friends unto us, and dispersed our enemies being overcome; so that the Briggad coming together, such as were alive missed their dead and hurt Camerades."

According to Monro the King attributed the victory (under God) to the Swedish and Finnish cavalry; but among the foot it was the Scotch Brigade which earned most thanks and commendation. In his general discussion of the battle Monro enumerates a long list of reasons for the victory, mixing impartially the religious with the military and technical; but the principal cause in his view is still the King himself, who in his own person was worth more than twenty thousand men:

"O would to GOD I had once such a Leader againe to fight such another day in this old quarrel! And though I died standing, I should be perswaded, I died well;... he that would labour an Army as Gustavus did, he will finde fruite, yea even the best that groweth under the Empire, good Rhenish and Necker wine, not onely for himselfe, but for the meanest Souldier, and that unto excesse, which bath made me sometimes complaine more of the plenty our Souldiers had after this victory, through the abuse of it, then ever I did before for any penury".