Roman war with the Dacians - art by Giuseppe Rava ~ Of special note is the extra armour the legionaries wear on their arms. This was developed during the Dacian wars to help protect the Romans from the falx, a scythe like weapon the Dacians used with great effect against the Romans' Lorica segmentata armour. It sliced right through!
Emperor's Children Aspring Champion. The Emperor's Children are a Traitor Legion of Chaos Space Marines who devote themselves solely to the service of the Chaos God Slaanesh, the Prince of Pleasure, though they were originally the Imperium of Man's proud III Legion of Astartes.
Mithridates VI wearing a lion head, 120 BCE- 63 BCE. King of Pontus, centered below the Caspian Sea, was the Hellenistic enemy of Rome. He controlled most of the shores of the Black Sea and its huge resources. In his first war, he conquered all of Asia Minor, where he massacred resident Romans and Italians. He took Greece before Roman legions forced him back, in his 3rd war he was pushed into Crimea where he killed himself.