How did the Roman army change over time?

From the inception of Rome as city, military and violence was ingrained in Roman culture. A society made primarily of men, most Romans had to have military experience in order to survive in the city. As the city grew and the government expanded, not everyone was capable nor had the means to gain a military background. Therefore, people who came from wealthy backgrounds that were able to afford the expsenive equipment and time away from home stepped up as the Roman military. Since Rome had no official organized army, these group of men who led these military expeditions to expand personal wealth as well as Roman wealth had to be honored by the government in order to encourage more of this action. This was evident by the establishment of the concilium centuria where the calvary was the class with the greatest number of votes, eventhough they had the smallest population in Rome. Honor and glory in Roman politics therefore became intrinsically tied to military success. If one wanted to be a successful Roman politicain, he had to build his own army and bring back a triumph to Rome. This would eventually escalate to the point that politicains would make up wars in order to gain more glory.