The Lion of the North: The Military Exploits of Gustavus Adolphus 

Military History witnessed its fair share of innovators over the centuries. From Gaius Marius in the Age of Antiquity, to Napoleon in the Early Modern Era, it is an extensive list to be certain. One of these pioneers was Gustavus Adolphus. This 17^th Century Swedish monarch, and his credibility as an innovator, cannot be understated. His actions elevated Sweden to a European military hegemon, laying the foundations for a new style of warfare that would define a century. Through this article, one shall witness the novel reforms of Gustavus Adolphus and how they fared in practice during contemporary conflicts, such as the Thirty Years War. 

Ascending to the throne at just the age of sixteen in 1611, the young king faced a daunting challenge. Sweden, far from a dominant power in the Baltic (let alone Europe), found itself already fighting three separate wars against Denmark-Norway, Russia and Poland-Lithuania. Nevertheless, Gustavus Adolphus set to work immediately. In 1613, peace was secured with Denmark-Norway, which guaranteed much needed breathing room to assess the capability of the Swedish Army. 

During the period, many contemporary armies relied heavily on mercenaries. Whilst experienced in their craft, these soldiers of fortune were often motivated by self-interest and self-preservation rather than an unwavering devotion to their client. Thus, Gustavus Adolphus looked internally rather than externally for his soldiers. Sweden became one of the first countries to implement a large-scale national militia that acted as a regular army. These men were meticulously drilled to the level of a professional soldier, and from this, they gained an iron-willed discipline. 

Furthermore, innovation was not only seen in the Swedish army’s recruitment, but also in its tactics. Before we discuss the tactical changes, it is important to understand the contemporary consensus on European military. Traditional European armies fell into either two military schools of thought: the Spanish and the Dutch. The Spanish method employed heavy bodies of infantry in square formations (tercios) flanked by cavalry that aimed to smash through the enemy in an unstoppable advance. However, with such mass of troops came limited mobility and stiff rigidity. The Dutch method was the complete antithesis. Employing small units (battalions), it enabled greater mobility on the field of battle, but their size meant that battalions were comparatively weak in prolonged engagements. In addition, most European armies employed an even balance of pikemen and musketeers, supported by cavalry and a few artillery pieces. 

Gustavus Adolphus created an effective balance between the two schools. Infantry was organised into brigades which provided impressive firepower and effective mobility, as their ranks were only three men deep. There was also a greater focus on the musketeer. The Swedish king noticed that warfare was gradually becoming a more ranged affair rather than close quarters fighting. Henceforth, musketeers were drilled vigorously to ensure a higher rate of fire, whilst being provided with lighter muskets to facilitate manoeuvrability. During this period, European cavalry often took a passive approach in battle; charging up to the enemy ranks to fire off their pistols before disengaging, which would be repeated until the enemy ranks had been sufficiently weakened. Under Gustavus Adolphus, Swedish cavalry would instead fire off their pistols beforehand, allowing them to charge into the enemy with drawn sabres. They would also be supported by musketeers on the flanks, creating a strong synergy between infantry and cavalry. 

Finally, artillery received arguably the greatest attention for the Swedish innovator. Cannons were categorised by the weight of their projectile, such as the 3-pounder and 6-pounder. Gustavus Adolphus favoured the 3-pounder. Not only were these artillery pieces easy to produce, but they were also extremely mobile, as they only required a single horse to move it and a team of a few men to operate them. Meanwhile, artillerymen reached meticulous training to improve their accuracy and rate of fire. After years of reforms, the Swedish army was finally a professional fighting force, ready to test itself in battle. 

In 1617, Gustavus Adolphus obtained a treaty with Russia after a minor campaign, which enabled Swedish territorial gains in Ingria and nominal control over the Eastern Baltic. His attention then turned to the Polish Lithuanian Commonwealth, a formidable foe. The Polish Lithuanians had routinely bested Swedes over decades of fighting, as their infamous winged hussars annihilated Swedish armies at Kircholm in 1605 and Klushino in 1610. But this time would be different. At Gniew in 1626, the once unstoppable wave of winged hussars was driven back by organised fire from Swedish musketeers, whilst at Dirschau in 1627, Swedish cavalry proved more than a match for their Polish Lithuanian adversaries. With these victories secured, peace was procured in 1629 which guaranteed Sweden a share of toll dues from Polish Ports. Now, Gustavus Adolphus found himself the undisputed hegemon of the Baltic. However, he wanted more. 

Soon, the king’s gaze drifted south to the lands of the Holy Roman Empire, which was amid the Thirty Years War. This bitter conflict had been raging on since 1618 between the Catholic imperial Habsburgs and the Protestant German princes with little signs of slowing down. With the protestant forces on the backfoot, Gustavus Adolphus, deeply devoted to his faith, sought to come to the aid of his German coreligionists. Albeit there were ulterior motives behind this intervention. By weakening the dominant Habsburgs, the Swedish King could make territorial gains in Northern Germany, alongside increasing his influence beyond the confines of the Baltic. Swiftly arriving in Northern Germany in 1630, Gustavus Adolphus made several alliances with the German Protestant princes, whilst simultaneously marching his army down south into the Catholic heartlands. 

It was north of Leipzig at Breitenfeld on September 17^th, 1631, where the Swedish King would meet a proper challenge: 35,000 Imperial soldiers under the command of Johann Tserclaes, the Count of Tilly. Tilly was a formidable veteran of the Thirty Years War, having routinely inflicted crushing defeats on the Protestants. Likewise, the Imperial army was just as ferocious as their commander. The centre composed of the tercios that had proven unstoppable to this point with cavalry on both flanks, most notably the black cuirassiers under Pappenheim on the left wing. The Swedish force outnumbered the Imperials with a force of 39,000, but 16,000 of it were Saxons, inexperienced and of weak morale. Gustavus Adolphus arranged his Swedes on the right wing and centre, whilst his Saxon allies remained separate on the left wing.  

The battle began with an intensive artillery duel between the two belligerents for two hours. Thanks to their superior training and more mobile artillery, the Swedes came out at an advantage. Impatient and impetuous, Pappenheim marshalled the Imperial left wing to assault the Swedish right wing, which was composed of cavalry and musketeers. As the black cuirassiers charged forward to fire off their pistols, they were met with a hail of bullets and then the shining sabres of the Swedish cavalry. After a brief melee, the Swedish horsemen disengaged before returning in a renewed charge, allowing their musketeers to fire a devastating volley and then reload in the interim. This occurred seven times before the Imperial left wing broke. Seeing the annihilation of his left wing, Tilly ordered his centre and right wing to advance against the weaker Saxon left, hoping to encircle the Swedish centre. Faced against professional veterans, the Saxons were put into flight, which threatened to expose the Swedish Centre. 

However, here was where the seeds of Gustavus Adolphus’ military labour came to bear fruit. With alarming mobility and discipline, the Swedish centre turned ninety degrees to meet the flanking manoeuvre, along with its entire artillery, firing into the tightly packed tercios. To make matters worse, the victorious Swedish cavalry on the left wing had swept round and enveloped the Imperial army. They even grabbed hold of the cumbersome Imperial artillery pieces, now firing at the backs of their former owners. Thus, a wounded Tilly was forced to pull his army in retreat with around 7,000 men dead compared to 2,100 Swedes. 

After this glorious victory, Gustavus Adolphus pursued the advantage by seizing Mainz in December 1631. Imperial misfortune continued into the following year. On 15 April 1632, Tilly’s force was encircled by the extremely mobile Swedish army at the Battle of Rain, in which the elderly general was mortally wounded, dying two weeks later. With their greatest commander dead, the Imperials were in disarray, all while Gustavus ran amok in Bavaria. This dire situation required a miracle. That miracle was Albrecht von Wallenstein. 

A distinguished general in his own right, Wallenstein was dismissed in 1630 due to his ambitious nature but was begrudgingly recalled in 1632 by the Habsburgs. Immediately, he set to work reforming the shattered Imperial army. Such was the tactical genius of Gustavus Adolphus, that even Wallenstein adopted Swedish tactics for his force. Lighter artillery was employed (albeit these were 6-pounders compared to the Swedish 3-pounders), whilst a greater emphasis was placed on the imperial musketeers. This proved successful against the Swedes at Alte Veste during the 3^rd and 4^th September 1632, in which the fortified Imperials repulsed Swedish assaults. Following on from his victory, Wallenstein pushed into Saxony, chasing the Swedish king in hot pursuit. 

South of Leipzig near Lützen on 16 November 1632, the climatic showdown between Gustavus Adolphus and Wallenstein would take place. Caught in a precarious position, Wallenstein was forced to entrench his force of 20,000 as he awaited the return of Pappenheim and his soldiers who numbered around 3,000. Aiming to strike the Imperials before they received reinforcements, the Swedish king quickly arrayed his 19,000 strong army for an assault on Wallenstein’s position. 

Through a thick fog, the Swedish line advanced swiftly like spectral wraiths. Gustavus Adolphus personally led his soldiers on the right wing into battle as they crashed into the weakened Imperial left wing, which following from the Swedish example, contained a mix of musketeers and cavalry. After ferocious fighting, the Imperial left was forced into retreat, but it had bought enough time. Pappenheim and his reinforcements arrived at the battlefield. In a reckless charge, they successfully forced back the Swedish right at the cost of their own general. However, Pappenheim would not be the only general to fall in this battle. 

Witnessing his centre buckling under Imperial pressure, Gustavus Adolphus and a detachment of cavalry hoped to rally the infantry and renew a push against the exhausted Imperial centre. However, the Swedish king became lost within the thick fog that had engulfed the battlefield and was ambushed by several imperial cuirassiers. At just thirty-seven years old, Gustavus Adolphus was slain in combat. Incensed by their beloved king’s death, the Swedes wildly pushed forward with the determination of reclaiming his body, as the bloody fighting intensified. With darkness drawing near and losses mounting, Wallenstein orchestrated a tactical retreat from the field, leaving the Swedish army with victory. A pyrrhic victory.  

Yet the innovations of Gustavus Adolphus did not die with him at Lützen. On contrary, they flourished. Armies of national conscripts gradually replaced the reliance on mercenaries, with professionalism heavily emphasised. The pike became obsolete in favour of the musket and later rifle. Mobility cemented itself as a key tenant of European armies for centuries, even up to the time of Napoleon. Thanks to these military reforms, Sweden rose from a mere minnow to a big fish in the European pond and would remain as such for over a century. Such was the legacy of Gustavus Adolphus. 

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