Who's This? He's the Roman dude on page 13 of Who's Who's 9th volume.
How you could have heard of him: He was whisked to Dinosaur Island with warriors of other eras in 2008's underwhelming The War That Time Forgot limited series. More recently, he was featured in a chapter of Walt Simonson's The Judas Coin.
Example story: The Brave and the Bold vol.1 #2 (1955), reprinted in The Best of the Brave and the Bold #3 (1988)
Not that there's much commitment to non-superhero, especially historical, fare at DC these days (or perhaps I should say, on the part of DC's readers), but with the success of movies like Gladiator, and television shows like Rome and Spartacus, wouldn't it have made sense to at least try to tap into the Roman Empire's pop culture allure in the 2000s? Maybe the next "Sword of Sorcery"-type series will feature the swordsmen that first appeared in those early issues of The Brave and the Bold - Golden Gladiator, Viking Prince, and Silent Knight. They could do worse.
Who else? The Grim Ghost is next. He has to be.