As the war clouds gathered over Europe at the end of the 18th Century, most nations published new regulations. Prussia did so in 1788, France in 1791, Britain published infantry regulations in 1792 followed by cavalry regulations in 1796 and Russia brought out a pair of manuals in 1796 and 1797. Of all the major nations, only Austria clung to their somewhat outmoded 1769 regulations, which were in fact little changed from their 1749 regulations. 
These various regulations were, in themselves, developments of those previously used in the 18th century but, with the exception of the Austrians, there were some significant changes to all that had gone before. In particular, the theoretical assumptions underlying the tactics to be used were beginning to change. The tactics of Marlborough had relied on infantry firepower, with troops closing to the enemy then commencing a continual cycle of firing by platoons until the enemy collapsed.  Military theorists of the 18th century had previously considered alternative methods of attack to this deliberate controlled wave of fire. In the early 18th century the French Marshal Puységur promoted the use of hasty à prest attacks, during which the troops did not fire but closed to their objective as quickly as possible.  Regardless of whether attacks were deliberate or hasty, traditional 18th century battle formations were linear, or ordre mince as the French called it. Chevalier de Folard, writing in the 1720s, proposed an alternative attack formation in heavy closed columns which he named ordre profond.  In the 18th century such methods were occasionally used when assaulting strongpoints but traditional formations predominated. The essential problem was that such concentrations of troops provided ideal targets for artillery. The solution was rapid transition between heavy columns and lines but this was not possible under the processional or parallel deployment methods then in use. The Prussian army had traditionally used a rolling advancing fire, similar to that of Marlborough’s Anglo-Dutch forces, but delivered at a series of decreasing ranges as the Prussian infantry closed to the enemy. Frederick the Great abandoned this method in favour of hasty à prest attacks but during the Seven Years war introduced the compromise of an initial series of volleys to soften up the enemy followed by a rapid attack, delivered without firing. 
All of the various threads of these 18th century developments were brought together by the French theorist Guibert, whose Essai general de Tactique published in 1772 proposed a flexible mix of columns and lines, with the ability to rapidly transition between them.  This flexibility and rapid formation changing was made possible using the relatively new perpendicular deployment methods developed by the Prussians during the Seven Years War, but not actually used by them to any great degree during that conflict. The tactical concepts proposed by Guibert were promptly adopted, directly or indirectly, by most of the major nations.
Although Guibert’s new tactical concept relied on the development of several threads of previous thinking, nevertheless his synthesis of them into a unified structure was truly revolutionary. In particular he saw how Prussian experiments in perpendicular deployment and reduced distance columns were the key to the whole new way of making warfare.
For comparison, the classic 18th century deployment method is shown at Diagram 1.
As explained in the previous article on Tactical Developments in the 18th Century, troops marched to the battlefield in Columns of Route, which were full distance columns on relatively narrow frontages, typically half-company, quarter-company or sixes. The small frontage made it possible for such a column to wheel around obstacles or march along roads, whilst being at full deploying distance made it easy to increase or decrease the column frontage. If operating in very open county it was possible to form columns of route on the same company or half-company frontages as tactical columns but more often columns of route were formed on quarter-company (typically section of 8 men frontage) at most. The smallest practical frontage was by sixes (fours being preferred by the British due to their two deep formation) to avoid what Nafziger calls “the accordion effect”  whereby columns lengthen out to a greater distance than the same number of troops would occupy when in line. British regulations gave specific guidance on frontages of columns of route, indicating a maximum of half-company frontages, and also clear direction not to allow such columns to lengthen out as follows :
“1. — All marches are therefore made …..never on a less front than 6 files where the formation is 3 deep, or 4 files where it is 2 deep, nor does any advantage arise from such a column, if it is an open column, exceeding 16 or 18 file in front, where a considerable space is to be gone over.
2.— At no time whatever ought a column of manoeuvre or of route to occupy a greater extent of ground in marching than what is equal to its front when in order of battle; no situation can require it as an advantage.” 
As they approached the rear of the battlefield frontages of these columns were increased to platoon widths but the column still remained at full deploying distance. Just outside the maximum range of enemy artillery these columns would wheel into line, using processional or parallel deployment methods, which required such deployments to be made from full distance columns. This was a lengthy process, which also displayed the vulnerable flanks of every platoon to the enemy, hence the need to conduct it outside artillery range.  Deploying into line at this distance from the enemy also effectively meant that the formation change took place outside the range of any possible interference by enemy infantry or cavalry.
All movement towards the enemy would then be in line, as shown in Diagram 2 below, with each infantry battalion covering the flanks of the next one and cavalry posted on the wings to protect the vulnerable outer flanks.
By the end of the Seven Years War this general concept had been modified to the extent that an army might be broken into several components which attacked separately, but nevertheless each of them did so using the principles outlined above.
Towards the end of the Seven Years War the Prussians had experimented with perpendicular deployment, by which battalions deployed into line whilst still facing the same direction as in column. Although they did not use this method much during the wars the drill regulations of all nations which were published after the Seven Years War adopted it.
Under Guibert’s concept, shown at Diagram 3, troops still marched between battlefields in Columns of Route, with narrow frontages at full deployment distances, identical to those used by their 18th century predecessors.
As they approached the rear of the battlefield they increased their frontage but maintained their full deploying distance, again exactly as 18th century armies did. Once on the battlefield, in other words at the extreme range of enemy artillery, 18th century troops would have formed line but Guibert’s concept called for troops to remain in column, or possibly a flexible mix of column and line, as they advanced towards the enemy. Guibert’s concept called for line to be formed, not at extreme artillery range, but just before extreme musketry range, with troops remaining in column in the manoeuvre zone between these points. The advantages of this concept were speed of movement and flexibility. In theory columns and lines could move at exactly the same selection of possible march rates, but in practice there were several inhibitions on lines using higher march rates which did not apply to columns. Columns could also wheel much faster than lines and therefore could develop attacks in directions which achieved tactical surprise. It cannot however be stressed strongly enough that Guibert’s original concept called for such columns to nevertheless form line prior to the final assault. Guibert’s concept therefore relied on attacks mounted by battalions manoeuvring in column, developing faster and in unexpected directions compared to those in line, but still forming line (as the best formation for both delivering and receiving fire) at a point shortly before the range of enemy musketry fire.
One of the main problems of manoeuvring on the battlefield in column was that such units were potentially vulnerable to attack by enemy cavalry. This was one of the reasons why 18th century lines advanced as an entity, with each battalion covering the flank of adjacent units, and used cavalry to protect the outer flanks of an army. Guibert’s flexible concept not only made every battalion manoeuvring independently on the battlefield much more vulnerable to attack by cavalry but also freed up the cavalry from acting as main army flank protection so that they were available to roam the manoeuvre zone attacking enemy infantry columns. In the classic 18th century battle layout cavalry had to be placed on the flanks to maintain the integrity of the main infantry battle line. Under Guibert’s system this no longer applied and cavalry could be much more flexibly positioned to take advantage of the tactical situation.
The solution to this vulnerability of battalion columns to cavalry attack in the manoeuvre zone was for them to be able to form square quickly. Full distance columns took effectively the same time as lines to form square, some one to two minutes. Classic 18th century tactics solved this problem by keeping the entire battle line as an entity therefore there were no isolated battalions needing to form square. The more flexible movement of individual battalions on the battlefield required a different solution.
The great disadvantage of the earlier processional or parallel deployment methods was that the battalions had to be at full deploying distance. Guibert realised that reduced distance columns, as experimentally used by the Prussians during the Seven Years War, could form squares in less than half of the time taken by full distance columns. He therefore proposed that all columns operating in the manoeuvre zone should be half distance, quarter distance or close columns, which could thus form square faster than a cavalry attack could develop.
Once these reduced distance columns reached the enemy line, or under Guibert’s concept, a point just outside enemy musketry range, they needed to be able to form line themselves as shown in Diagram 4.
If these troops had remained in full distance columns and used 18th century processional or parallel deployment methods, they would have taken an excessively long time to transition into line. Early 18th century processional deployment could take up to two hours  and even the speedier parallel deployment of the mid 18th century normally took some 20 to 30 minutes. To have carried out such a deployment just outside enemy musketry range would have been to court disaster since the enemy could easily have advanced a few paces to pour fire into an army from close range whilst they attempted to change formation. Reduced distance columns could not in any case use processional or parallel deployment methods because anything less than full distance meant that companies were too close to each other for such wheeling into line to work. The solution proposed by Guilbert was for such deployments to be achieved by the perpendicular deployment methods pioneered by the Prussians during the Seven Years War with each battalion carrying out a traversierschritt or en tiroir conversion, thus reducing the transition to a matter of less than half a minute. A further advantage of Guibert’s system is that each battalion could carry out such a conversion from column to line independently so that some battalions could deploy into line whilst others remained in column should the tactical situation make this desirable. In particular reserves invariably remained in column under Guibert’s system because they could then be manoeuvred more flexibly to respond to the developing battle.
The advent of more flexible battlefield tactics, commencing from Frederick the Great’s echelon attack and developing into the concept of separate axis of attack for elements of the force made perpendicular deployment even more attractive. 18th century armies moved forward in lines because each battalion then had its vulnerable flanks protected by its neighbour. However, in the quest for tactical advantage over an enemy, greater speed could be achieved by moving forward in column.
Interestingly, one of the earlier sets of regulations to be published which followed Guibert’s principles was the Regulations for the Order and Discipline of the Troops of the United States, originally produced in 1779. This small manual written by the Prussian officer Baron von Steuben includes diagrams showing perpendicular transition from column into line, which was an essential cornerstone to Guibert’s concepts. The same manual also shows both open and close columns, and furthermore describes the formation of a solid square from a close column as a rapid anti-cavalry drill. 
In several countries thought provoking books on tactics were published shortly before the regulations themselves, invariably acting as a precursor to those regulations. In 1787 Isaac Landemann, Professor of Fortifications and Artillery to the Boyal Military Academy at Woolwich, published his translation of the latest Prussian tactics as described by an anonymous Prussian Officer.  These are very similar to the Prussian regulations published the following year in 1788 and both publications definitely showed the influence of Guiberts thoughts. This is an interesting cyclical concept since many of Guibert’s ideas were themselves developed from Prussian tactical experiments. In particular these showed open and close columns, forming line by perpendicular deployment, and forming both hollow and solid squares. The French regulations of 1791 followed a similar pattern in that they built on the previous French regulations, modified by Guibert’s theories, and borrowing some aspects from the Prussian regulations. In much the same way, in 1788 David Dundas published his “Principles of Military Movements”  which drew heavily on Prussian drill and experience but by doing so accepted the essence of Guibert’s new thoughts. Some modern commentators have suggested that British tactics were still a throwback to the earlier 18th century linear concepts but this does not reconcile at all with Dundas’ own analysis in his book :
“Having once taken up in forming in line of battle in the processional manner, which was then the only one known: and when such line was once formed, it was difficult to make any considerable alteration in it, without much previous explanation, and endangering the order of the whole…..It was reserved for the King of Prussia to discover in the mechanism and application of the marching and Close columns, a simple remedy for all these defects, and to apply its principles to the training of all bodies great or small.” 
Dundas, writing in 1788, but drawing heavily on his attendance as an observer at Prussian military manoeuvres in Silesia in 1785, goes on to give an illustration of these new Prussian tactics in practice :
“When he approaches the enemy, it is at the head of a strong advanced guard, behind which his columns are collected and combined, according to circumstances. – In this situation, he delivers his future dispositions; the heads of his columns are carried to their several given points; distances are just; the celerity of forming is great.” 
Following publication of his book Dundas was invited to write a new set of regulations based on the principles he had outlined. The result, the British 1792 regulations, produced a development some elements of previous regulations, modified by this new tactical concept. It is noticeable that many aspects of these British 1792 regulations were very similar to the 1788 Prussian regulations which were themselves influenced by Guibert. Finally, the Russian 1796 and 1797 regulations were again much influenced by the 1788 Prussian regulations.
In summary then, the drill regulations adopted by all nations in the period 1788 to 1792 clearly showed the intention to use reduced distance columns to manoeuvre in the battle zone (between the extreme ranges of artillery and musketry) but still to form line prior to any actual combat. The use of columns in this zone enabled faster movement and could be used on multiple axis attacks in order to confuse the enemy as to the real intention of the attackers. All nations continued to use line for defence against infantry, since this produced the maximum firepower. The drill regulations envisaged that columns would deploy into line at the extreme range of musketry so that they could engage the enemy in a firefight on equal terms.
An examination of the detail of these various regulations shows how similar they were. All contained the basic drill elements familiar to the earlier 18th century manoeuvres as outlined in my previous article on Tactical Developments in the 18th Century. However, the Prussian, French, British and Russian regulations published in the period 1788 to 1797 also contained the essentials of Guibert’s new thinking. Only the anachronistic Austrian 1769 regulations remained uninfluenced by this new tactical concept.
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