Another serious PoD man might be Sertorius
See:
http://en.wikipedia.org/wiki/Fortunate_Isles
Quote:
Plutarch, who refers to the "fortunate isles" several times in his writings, locates them firmly in the Atlantic in his vita of Sertorius. Sertorius, when struggling against a chaotic civil war in the closing years of the Roman Republic, had tidings from mariners of certain islands a few days' sail from Hispania:
“ ...where the air was never extreme, which for rain had a little silver dew, which of itself and without labour, bore all pleasant fruits to their happy dwellers, till it seemed to him that these could be no other than the Fortunate Islands, the Elysian Fields.[1] ”
It was from these men that Sertorius learned facts so beguiling that he made it his life's ambition to find the islands and retire there.
http://en.wikipedia.org/wiki/Quintus_Sertorius
about 5 generations before the Empire and Tiberius.
( I do not only know how discovery and openning of the Americas would reflect onto the evolution of RE later ITTL ).