In this short essay I will attempt to chronicle the transformation of the French Republican Army from a volunteer army made up of professional soldiers and willing citizen-soldiers in a large mass of military serfs in the 1789-1794 period.
I know this topic will be highly controversial but I personally believe it provides a useful discussion and reflection topic in the defense debate. Any criticism, as long as it’s constructive, is highly welcome.
The armies of the Ancien Regime were, essentially, volunteer in nature. France had traditionally three sources of recruits.
The first, and most important, were the great cities like Paris, Lyon and Toulouse. Recruiters particularly targeted paupers, easily attracted by a steady, if meager, paycheck and the promise of food and lodge, and the younger sons of artisans and shopkeepers, who could not hope to take over the family business and were usually doomed to a lifetime of perpetual misery.
The second were the country estates of certain noble military families. Members of these families, serving as military officers, were regularly given six-month leaves (semestres) to recruit troops for the army. Military life, as hard as it was, was usually seen as an attractive alternative for the younger sons of peasant families. Moreover these men usually ended up serving under the same noblemen who had recruited them, often in highly regarded cavalry and artillery unit.
The third were the many foreign (Swiss, Bavarian, Irish etc) regiments serving France. These were of very varied quality and each had its own way of finding recruits. 
In dire needs a fourth source of recruits was available, the so-called milice. The milice provided a pool of available manpower to be incorporated into regular units in time of need. It fell almost exclusively on peasants, who were chosen by lot. As peasants rightly detested the milice, it was rarely used as it could spark riots and even rebellions in the countryside.
Generally speaking the armies of the Ancien Regime were overwhelmingly urban in origins, apart from cavalry and artillery units, which needed taller and stronger men and hence made a point of recruiting strong country lads.
The French Army had an excellent fighting record, going back to when the Prince of Condé inflicted a crippling defeat upon the formidable Spanish tercios at Rocroi in 1643 during the Thirty Years War. However, the debacles of the Seven Years War (1756-1763), especially when facing the Prussian regiments of Frederick The Great, had caused a number of reforms. Most of these aimed at copying the Prussian system and were much resented by men and officers alike.
Of special interest were the disciplinarian reforms carried out by the Count of Saint Germaine in 1767, which introduced Prussian-style punishments. Particularly hated was the beating by the flat of the sword, which was to be carried out in front of the whole regiment and aimed not at punishing the soldier but at humiliating him. Also officers could punish soldiers at whim, just to “give an example”, even if no breaches of discipline or crimes were committed.
While there were many reasons why the French army didn’t intervene to save the monarchy in 1789, the detested Prussian-style disciplinary system is surely one of the most important reasons.
When Emperor Leopold II issued the Padua Circular in 1791 after Louis XVI attempted to escape from Paris, the National Assembly realized the armies of Europe were about to march on their borders, hence they took a good look at their armed forces. 
The regular army had much deteriorated since 1789. The officer corps, overwhelmingly made up of noblemen, had been bled white, desertion had weakened the line infantry and material shortages (compounded by a series of idiotic cost-cutting measures implemented in 1789) had literally destroyed the cavalry. 
France had a ready reserve of manpower, the so called National Guard. Partially inspired by the Marquis de La Fayette, it owed its existence to a series of panics (collectively called the Great Fear) about plots and brigandage. Wholly composed of volunteers, predominantly urban and bourgeois in composition, it was however of limited military value. Members acted more as a constabulary since they had only limited military training.
After much debate, it was decided to call upon the National Guard to provide 100,000 volunteers (roughly one every three Guardsmen on roll). The men responded enthusiastically, and the first 20,000 men marched toward the Northern border in July 1791 already.
These men are collectively known as the Volunteers of 1791. They served in their own units, predominantly local in nature, and under officers chosen by themselves: these were often former privates and NCO’s with some military experience.
Their terms of contract were to serve for a single campaign, after which they were free to return home.
After the war broke out in 1792, the National Assembly called for more volunteers, again to be supplied by the National Guard: on paper these numbered 70,000 men.
Since the Paris National Guard responded in particularly enthusiastic fashion, the Assembly decided to replace them with the so called féderés: they asked each canton of France to send five volunteers to Paris to form an armed force which was to act both as a constabulary and as a last line defense force. Again, the response was overwhelming and 20,000 man marched to Paris. These were formed into eighteen batallions.
As more front opened up, in July 1792 there was yet another call for volunteers, comprising 50,000 recruits for the old line army and enough men to form 42 new battalions. This time recruitment was open not to just to former soldiers and National Guardsmen but to “all citizens capable to bear arms”.
This time, the first signs of strain appeared: some cities (like Paris) and departments (like Haute-Saone and Calvados) responded with incredible enthusiasm, raising far more men than they were asked for. Other cities and departments responded with far less enthusiasm, to the point the National Assembly authorized both recruitment bounties and even hiring mercenaries to meet quotas.
These men were collectively known as the Volunteers of 1792. The early National Guard contingent of 70,000 men was pretty much similar to the Volunteers of 1791 but later recruits were strikingly different. They were mostly lower class (some writers characterized them as “an army of sans-culottes”), highly politicized, poorly equipped and sorely lacking in drill and discipline.
In February 1793 the Convention  learned the Republican Army, which totaled almost half a million men in November 1792, had shrunk to less than 300,000. After some early reverses (mostly dictated by the inexperience of the vast bulk of the troops) it had developed in an excellent fighting force during 1792, able to defeat the much feared Prussians at Valmy and the well drilled Austrians at Jemappes. However winter treated all XVIII century armies harshly and the hastily expanded and very poorly supplied Republican army suffered terribly from lack of food, clothing and even shelter.
Apart from tear and wear, other factors were at play.
Most Volunteers of 1791, having reached their terms of engagement and satisfied with having beaten the dreaded Prussians, simply marched home after Jemappes.
Many Volunteers of 1792 exercised one term of their contract, according to which they could leave their units after giving their commanding officers a two month notice.
Others simply deserted the ranks when cold weather, illness and famine began taking their toll.
The Convention not only believed it could maintain an army of half a million on France’s borders, but was convinced it could be expanded to 800,000 men. Yet it was apparent Republican fervor was on the wane: ironically Kellerman’s and Dumouriez’s victories did their part in stamping it out, as many believed La Patrie was now safe from foreign threats.
To make up for this, the Convention took the unprecedented step of introducing conscription, by calling for a levy of 300,000 men. By very complicated computations, each department was assigned a quota based on 17% of its male population less the Volunteers of 1791 and 1792 still serving in the army.
However, as the Vendée was already on the brink of open rebellion, the Convention pulled short of universal conscription. The Levy of the 300,000 aimed at men aged 18-40 who were unmarried or widowers without children. Voluntary enlistments were to be preferred however, should insufficient numbers of willing volunteers step forward, the law provided for compulsory enlistment to complete the quota. The Convention also left to local authorities to decide how conscripts were to be chosen and authorized the hiring of replacements.
To many peasants, this system smacked of the old and much hated milice. Whole communities taxed themselves to hire substitutes from the outside. Conscripts deserted in large numbers while being marched to depots. And, in spite of everything, the Vendée rose up in arms against the Convention in March 1793. Worse still, when all was said and done, only half of the 300,000 ever reached army units and of these a large number (variously estimated between one quarter and one third) was made up of hired replacements.
Men at the front, be them generals, NCO’s or even simple Volunteers who had chosen to remain under arms, complained about the poor quality of these conscripts. Sergeant Alexandre Brault, a Volunteer of 1791 tasked with training and drilling a number of them, reported to his superiors “Dogs that were led about with blows from a stick are never any good”.
Ironically enough, the Vendée Rebellion had the effect of precipitating the introduction of full-blown conscription. As veteran army units were dispatched to the Vendée, the Convention decreed a levy of 20,000 men to be sent to the army as replacements. Another levy of 30,000 men was authorized in 1793 specifically to supply much depleted cavalry units with replacements. Again, voluntary enlistment was to be preferred, but as numbers proved well below the targets set by the Convention, most of the men from these levies were either unwilling conscripts or hired replacements.
France had thus unwillingly let out of the bottle the evil genie of “peoples’ wars” Louis XIV had warned about almost a century before.
Part 2 coming shortly…
 All armies of the Ancien Regime had large numbers of foreign mercenaries on payroll. Given the notion of Nation-State had not emerged yet it was relatively easy to insure a steady supply of recruits for these regiments even in time of war (see how both France and Spain maintained a large number of Irish regiments in the XVIII century during their wars with Britain).
 Louis XVI and his family attempted to flee from Paris to the Austrian Netherlands in June 1791, before being forced to turn back by troops loyal to the National Assembly. Emperor Leopold II of the Holy Roman Empire, already very wary of developments in France, considered this an unbearable crime against his family (he was Marie Antoinette’s brother) and on the 5th July 1791 while in Padua (ironically controlled by the Republic of Venice) issued a circular addressed to the sovereigns of Spain, Prussia, England, Russia and his Imperial subjects urging them to invade France and reinstate Louis XVI.
 While thousands of noblemen abandoned the army, many others decided to stay. Most of the finest generals of the Republican army were of noble birth: Charles-François Dumouries (the winner of Jemappes) was the scion of a noble Walloon family while François-Cristophe de Kellermann (the winner of Valmy and later Marshall of France) was the only son of a Saxon nobleman who served as an officer in a foreign regiment.
 The National Assembly renamed itself National Convention on the 20th September 1792. It was nominally France’s supreme constitutional and legislative body, but held vastly executive powers as well. It was disbanded on 26th October 1796 (4th Brumaire of the Year IV).