Did I say something wrong? Sounds like free lecture. How can I resist?

Well it happend because of many things. Marius wanted more than 'conscripts' who just pick up arms in times of invasion in the city of Rome itself. He wanted leet soldiers who train all year round. The early Republican system limited the recruitment pool to just property-owning Romans which was depleted due to conflicts in previous years. Slaves 'stole' job from poor Romans so they were never eligible to serve as they would never meet the strict requirements of owning things and all that.


If you were to sum it up in one sentence though I think it's ok to say Rome got too big. Marius needed an army to campaign in Numidia after all.