1. Introduction

The army prior to Marius’s military reform was primarily recruited using the class system described in the 6^th century BC, Servian Constitution. Citizens who were able to serve in the army were mainly from the top five property classes. Roman citizens who did not qualify for either of the property classes were classified in the sixth and the lowest class [1]. The sixth class was called proletarii or capite censi. The members in this class had no property so they could not afford to purchase their own equipment or a military campaign that lasted weeks. Therefore, the proletarii was usually exempt from military service [2]. Those who qualified were drawn into four consular armies each year in a lottery. This process of this lottery was conducted by the annual consuls in a ceremony summoning the entire popular assembly to the Capitol [3].

In the early republic, campaign season lasted only a few months. After a single campaign season, soldiers were dismissed and returned to their roles in civilian society. They would wait for next season’s call back into service. Service in the pre-Marian army was largely based on a sense of duty, honor and loyalty to the state. In most of the republics, enrollment in the Roman army had been a virtuous duty for the middle class, since they were mostly fighting for the protection of their own holdings and properties. The soldiers would then have their own equipment if they were recalled. It was rare for the Senate, nonetheless, to offer any form of compensation for repeating veterans. Soldiers had to rely on the booty that they were able to loot to repay the cost of the campaign [4].

2. Early Developments

Rome grew from a city-state into the dominant power in the Mediterranean region after the Macedonian and the Hannibalic Wars. As Rome expanded, its traditional military system met unprecedented challenges both internally and externally. The huge wealth brought into the empire by the recent conqueror of Macedonia and Spain made Rome more affluent than ever. Besides the vast wealth flowing into the Roman treasury, successful conquests also brought numerous slaves into Rome's market thus creating a large workforce of free labor. Many Roman nobles and equites who had acquired vast areas of ager publicus in Rome started to build massive latifundia, large landed estates that were mainly worked by slaves [5]. They produced wine, grain, and other agricultural products with close to no cost at all. Therefore, small Roman businessmen and individual farmers became unable to sustain their farm and were forced to sell them to larger landowners. In this way, Rome saw a decline of middle-class small farmers and the Roman population became gradually proletarianized. Proposals of reform that were designed to help the proletarii had been made several times but none of them were passed. The Marian reforms enabled the proletarii to serve in the Roman army and gave them land allotments to retire to. Roman proletarii, in this way, could return as middle-class through enlisting in the army [6].

External warfare had become increasingly demanding as Rome’s expansion left it at the doorway of unfamiliar enemies whom Rome had never fought against. The Parthian Empire in the east and the Germanicus and Celtic tribes in the north had brought the Romans disastrous defeats and led to the plundering of Roman provinces. These defeats strain that new borders and disloyal troops placed on the Republic underscored the need for competent reforms.

3. Decline of Middle-class Farmers

As demonstrated above, the traditional citizen militia placed compulsory military service on citizens who were in the adsidui class, those who came from the top five classes in the Roman census based on census qualifications. They were, theoretically, self-sufficient and affluent men who were able to pay for their own equipment and afford to be absent from their home for the periods of military service. In the Roman society before the 2nd century BC, these men largely came from the middle-class, who were small farmers working on a small piece of farm land. Small-farming was a successful way of life, occupied by small farmers and enabling them to meet the requirements for military service in the early days of the republic [7].

However, ever since the expansion of the empire and Rome becoming the dominant power in Mediterranean, small farmers’ lives became increasingly difficult. Before the Second Punic War in the 3^rd century, minimum requirement for military service was 11,000 asses, and after the beginning of the destructive Hannibalic War, Rome lowered its property qualification to 4,000 asses, and eventually to just 1,500 asses. Due to this influx of foreign wealth into the Roman elite, the economic conditions in Rome meaning the value of as was vastly less than that in the 3^rd century. As a result of economically backward qualifications, compulsory military service came to those proletarii who were by no standard an affluent middle class in the Roman society [8].

The small farming community was also hurt by the massive slave imports and the emergence of latifundia alongside the oversupplied slave market. The foreign wars provided abundant slave supply in the Italian slave-market. Thus, large landowners began to replace free labors with free-of-cost slave labors and effectively lowered the wage for the remaining free labors. The products of those latifundia outcompeted with the products of small, so these slave-run estates caused disastrous results as small farmers began to abandon and sell their land to larger proprietors, while unable to find work afterwards. They became a group of unemployed proletarii who could neither serve in the army nor make useful contributions to the economy [9].

The cycle of middle-class small farmers reducing to proletarii made Rome’s manpower pool insufficient compared to the size of the empire. As the demand for more troops grew, the property qualifications reduced, and the newly included citizens could not afford the prolonged campaign season, resulting in them getting outcompeted by slave-run latifundia and thus selling their property. With the decline of the middle-class, the size of the proletarii increased significantly. If these proletarii had been organized into legions, Rome would have had a leading manpower pool once again. Reforms in the Roman army would be needed to fulfill this goal [10].

4. The Reform

Gaius Marius, who was a ‘novus homo’ from the town of Arpinum, took lead in reforming the military. When he took command of his legion in the Jugurthine War in 107 BC, Marius immediately started to recruit new legions and fill up the old legions in the army [11].

During his recruitment campaign, Marius first levied auxiliaries from Roman allies and enlisted Roman veterans who fought in previous wars. These were conventional preparatory steps for wars, but he then he proceeded to recruit soldiers from all property classes including many proletarii who were prohibited from military service by Roman law [12]. This process of enlisting — irrespective of land or property — was later known as capite censi, ‘those counted by head’. It was originally used to describe the proletarii class. Many proletarii, devastated and unable to see a clear future in the contemporary economic environment, chose to join Marius’ army for the prospect of booty and looting [13].

Sallust notes that the proletarii had nothing to lose so they would take anything as reward for fighting in the army [14]. From here on, the new Marian Roman army’s fundamental goal for fighting had shifted from duty and honor to fighting for personal benefits and individual gains. Generals and army commanders became the patrons of the soldiers while soldiers would rely on their commanders for money gained from looting cities and winning wars, as well as land allotment once they retire. Marius also made serving in the army a career for the soldiers, who served for 16 years consecutively. Thus, Rome’s first professional army was established by Marius [14].

Besides the proletarii recruiting system, Plutarch also describes the army equipment reforms of Marius. In the conventional Roman army, poor people were not permitted in the army for their inability to supply their own equipment. Moreover, the Roman army was divided into four kinds based on property value and the amount of equipment each soldier could afford. Marius, in contrast, made commanders supply their soldiers with the equipment and have soldiers carrying tents, food and weapons. This turned the commanders into supply masters of the army, increasing the reliance of soldiers on them [15].

Marius’ army also trained differently with the traditional citizen militia. Prior to Marius, training for close hand combat was done individually. The more prosperous property classes could afford expensive training for themselves. Marius broke from this model and instead hired professional gladiators with exceptional hand-to-hand combat experience to train his newly recruited soldiers. His training was also continuous because his soldiers were professional soldiers who served continuously as well. With nationally supplied and standardized equipment, more efficient battle tactics, and professional training, Marius’ new army was much more efficient and capable than the traditional citizen militia [15].

The obvious impact of the reform was its establishment of a new kind of army. This kind of army significantly increased Rome’s military capability and efficiency for Rome. The reforms turned a traditional citizen militia army who fought for honor and the protection of their properties, into a professional trained army consisting of landless citizens. These citizens’ futures depended on their success wars so they were willing to fight ferociously to ensure victory. It is clear that the Marian army achieved more successful results than the traditional Roman army in the War against Jugurtha and the Cimbrian War [16].

In the war against Jugurtha, Rome's traditional nobility sustained humiliating defeats. Nonetheless, after Marius took command in 107 BC, Jugurtha had no advantage in the war. Jugurtha was eventually defeated and captured by Sulla. He was later executed during Marius’ triumph in 104 BC [16].

At the same time, Roman military strength was also seriously challenged in the North of the empire by Cimbrians and Teutones. At the Battle of Noreia, they defeated a 30,000 Roman legion led by Papirius Carbo (Con. 113), nearly killing them all. They again defeated a Roman force 80,000 men strong in the Battle of Arausio. This time as many as 120,000 Roman soldiers and camp followers were slaughtered [17]. The Germanicus tribes were extremely ferocious in battle and the Senate had to rely on Marius’ 'New Model Army' ' again to defeat this threat. Marius was elected consul for the second time in 102 despite this being forbidden by Roman law. He immediately started to prepare for the fight. He led his army to advantageous ground and defeated the teutones once and for all in the Battle of Aquae Sextiae. Marius then marched back to Italy the next year (he was elected consul for the third time in 101) and defeated the Cimbrian in the Battle of Vercellae. In both battles, the shared strength and hand-to-hand combat of the legions played the decisive role [18].

5. Conclusion

At the beginning of the 2^nd century BC, Rome’s citizen militia faced unprecedented challenges that threatened the republic and the traditional system failed to uphold those challenges resulting in the failures militarily and economically. Prior to the Marian reforms, the soldiers’ loyalty and motivations were based on public protection and the expansion of the republic. However, after Marius completely renovated the structure of the Roman army, the loyalty and the motivations of the soldiers changed. By activating the proletarii manpower, he transformed Rome’s citizen militia into a professional army, with newly recruited soldiers fighting for their own interests. The use of standardized equipment also increased the sense of honor and belonging after Marius eliminated the property class differences in the army. When fighting under capable leaders, those soldiers built a strong sense of trust and belonging since nowhere else in the Roman world could offer them at that time.

The soldiers in the Marian army also were able to fight all year long and were promised with booty and lands to retire to. Beyond Marius’ expectations, his reform laid the foundation for an army who was more loyal to commanders than to the Roman Senate and the. The Senate could have made official land allotment and payment for the soldiers to ensure their loyalty, giving the senate command of the most well-trained army in the ancient world. Instead, by actively opposing this army, the Senate doomed its own fate. The civil wars occurred later in the republic, centralized on utilizing the private army to achieve the political ambitions of the commander. And the ownership of Rome was no longer in the votes of the Roman people, but the de facto ruler of Rome was determined by the strength of private legions of political leaders. Thus, this increase in independence of political leaders marked the end of the century-long republican system, as well as the beginning of a new era in Rome, an era during which Rome was ruled by a single military and political dictator, an Imperator.