Cavalry

The Romans Are Coming!
Not every Roman soldier went everywhere on foot. The army also had cavalry, useful whenever it needed someone to move faster than a marching legionary.
They scouted ahead, patrolled roads, carried messages, escorted travelers, and chased down people who thought running from the Roman army was a good plan. They could also fight from horseback, with spears, javelins, shields, and swords.
Riding took real skill. The saddle helped hold a rider in place, but Roman cavalry had no stirrups. Add a shield and a weapon, and just staying on the horse starts to look like an accomplishment.
So when the Roman army needed someone somewhere quickly, the answer wasn’t “send a faster legionary.” It was “bring a horse.”