Triarii in action

[Paul Bardunias]

I am hunting for references of Triarii either moving into action themselves or acting as a bastion on the field behind which the other age groups rallied behind.  Anything helps, and thank you in advance.

[Steven James]

Of the top of my head, try Livy 8. 8

I will scrounge through my research and note what I come across. However, my research into the Roman fleet for the First Punic War is rather intense at the moment and like a black hole, taking all my waking hours.

[Paul Bardunias]

Of the top of my head, try Livy 8. 8

I will scrounge through my research and note what I come across. However, my research into the Roman fleet for the First Punic War is rather intense at the moment and like a black hole, taking all my waking hours.

Thank you very much.  I am all too familiar with the intellectual rabbit hole you have fallen into!

[Nathan Ross]

There's Livy 8.10, on the battle of Vesuvius:

[Manlius] cried out to the Roman triarii: "rise up now, and with fresh strength confront the weary enemy, remembering your country and your parents, your wives and your children, remembering the consul who lies dead that you may conquer." ... the triarii had got to their feet, fresh and sound in their glittering armour, a new and unforeseen array... and, raising a shout, threw the enemy's front ranks into disorder, and thrusting their spears into their faces, disposed of the fine flower of their manhood and went through the other maniples almost scatheless, as though their opponents had been unarmed, penetrating their masses with such slaughter as scarce to leave a fourth part of their enemies alive."

Also both Livy and Polybius on the Battle of Zama, where the triarii and principes were brought up onto the wings to support the main attack.