The roman army
The roman army was a crucial part in the rise of the Roman Empire
Only men can be in the army and they have to be in fit condition. He had to be a roman citizen to be part of the actual army but the people who wanted to join and they weren't roman citizens could join as auxiliary but they weren't trained as hard or paid as much but after the usual 25 years of service they would become roman citizens and their families would also become citizens. They would normally join at the age of 18-20 and most weren't married because after they serve the years required they would be rewarded with a pension or a piece of land to settle on. The best soldiers were the legionaries because they were the highest paid and trained
The weapons that the army uses were varied because it all depended on what you did best or your rank. Like there where some would use the arrow and be the best at that weapon. The swords were probably the most common weapon because they were the easiest to master.
The tactics they used were basically the first time they had ever been seen. They made a tortoise so that there would be less injuries and used short swords called gladuis that they really quickly jab whatever is in front of them causing more damage to the enemy then they could cause to you.