The Roman army was organized into legions of 5,000 men commanded by a legate. Each legion was divided into 10 cohorts made up of centuries of around 100 men each, commanded by centurions. Centurions were important leaders responsible for training soldiers. Each century had its own standard carried by an experienced standard bearer. Roman citizens between 18-20 years old who were at least 1.6 meters tall could join the legion for 25 years of service. Training included long marches while carrying heavy equipment and drilling maneuvers. Auxiliaries from conquered lands also fought for Rome, including cavalry and archers who were considered second-class soldiers.