I've got some good ones, but the recent winner would be Spurius Rabirius in my Scipii campaign.

It's around 200 BC. There are two powers in the East, controlling literally all of Asia and some of Africa: Pontus and Egypt. And they're allied. I'm busy driving Pontus out of Turkey and fighting for my life down in North Africa against the Egyptians.

In 193 Spurius, after getting married into the family, begins fighting. His first battle is with a meager army against two full-stack, high-tech armies of Egyptians, near Tarsus. He wins the battle, gets a heroic victory, and gets a famous battle marker.

Nearly 60 years later, he dies in Antioch after taking the Levant, the Nile cities, sweeping around through the desert, up past Seleucia, the Parthian starter cities, and finally conquering the last Pontic city, Hatra. He departs as my faction heir and with the rare epithet "the Great."

He may not have conquered as much land as the others, but he took on the two largest non-Roman empires at the height of their power and absolutely destroyed them.