What were the incentives for joining the Roman army before the Marian reforms?

Question

Before the Marian reforms, soldiers had to supply their own equipment. This did not exactly inspire anyone to form a professional standing army, especially since most were peasants who had to return to their fields after the military campaign.

So, in the period of the seven kings or in the early republic, why would anyone have wanted to join the army, especially if they had to pay for it out of their own pockets?

There were probably some who did it out of pure patriotic fervor, but what about the rest? The long periods of unrest between the patricii and plebeii, often caused by the lower classes being impoverished and indebted due to the costs of their military service, indicate that being a soldier was not lucrative. People abandoned their professions, went to the army paying it out of their own pockets, and seeing how many of them got into debt, it seems that the spoils of war didn't usually fully pay for their expenses.

Answer 1

Being an infantryman in the Roman armies of the kingdom and early republic was not consistently lucrative. To the average Roman citizen farmer there was always a distant hope of booty at the end of a campaign, even in the period you enquire about, but that was dependant upon the wealth of the current enemy. The spoils of war were not uncommon during this period of Roman history, as we are told by Livy in 5.12:

M. Furius in the Faliscan territory and Cnaeus Cornelius in that of Capenae found no enemy outside his walls; booty was carried off and the territories were ravaged, the farms and crops being burnt.

And 5.16:

With this they advanced by cross marches through the territory of Caere and surprised the Tarquinians as they were returning heavily laden with booty.

However, the fact remains that the majority of Roman citizens were effectively obliged to enter into military service if they qualified by falling under one of the first five census classes, a group of citizens which came to be categorised as the adsidui. These citizens were under a legal obligation out of a duty to the state they had a stake in to assemble when ordered by an executive bestowed with imperium as described in 2.27:

Appius was furious; he accused his colleague of courting the favour of the people, denounced him as a traitor to the commonwealth because he refused to give sentence where debtors were brought before him, and moreover he refused to raise troops after the senate had ordered a levy.

And in 5.10:

Then, again, armies had been enrolled for four separate wars in one levy, and even boys and old men had been torn from their homes.

Earlier in 5.16, it is noted that two consular tribunes, A. Postumius and L. Julius, were prevented from raising the levy by the tribunes of the plebs:

A. Postumius and L. Julius raised a force, not by a regular levy - for they were obstructed by the tribunes of the plebs - but consisting mostly of volunteers whom they had induced by strong appeals to come forward.

So even in the exceptional circumstances that a levy was prevented by a legal intervention, there were clearly incentives for Roman citizens to enlist for service in the ranks. Considering this, there would have been those who were willing to join out of the prospect of glory and booty (not too uncommon in a martial society), which may have been in order to attempt to pay back a debt or simply increment their wealth, and those who did it out of patriotic fervor and in defence of their homeland. Perhaps even retribution was an incentive for those who had suffered at the hands of a rival nation.

Answer 2

I have the impression that the pre-Marian Roman army was a sort of militia. Free men were more or less automatically enrolled when old enough and were expected to meet to train, provide their own weapons, and to serve if called up. So Roman citizens and allies didn't join the army, they were born as citizens of Rome or their native allied city or tribe and became part time soldiers as soon as they were old enough.

So unless I am wrong, almost no Romans or Italians "joined" the army before the reforms of Marius, they were all citizen soldiers legally required to serve when called up. They were all born as future part time soldiers.

Thus there were no "incentives", any more than there were for Americans drafted between 1940 and 1973.