Phc7006: Hint N° 2

To solve this, I would recommend to proceed in two steps

1) to deal only with the alphabetical characters.

If for instance the code word for the 4th group was BABY, CB19 would only need the BA to be applied onto CB, becomming DB19

2) then to deal with the numerals. Polynumeral shift. 4 coded groups, and there are 4 numeral positions in the year being taken into account. "Four groups of four, four numerals to bind them all ..."

Imagine the year is 1893 , the shift for that group would be +3, the group would become DB43

As for the year, it started by killing a snake and gave birth to a horse.Phc7006: Three relations of these events came to us through the ages. Plutarch is the most verbose : [i]he stood in silence and delayed to cross, reasoning with himself, of course, upon the magnitude of his adventure. Then, like one who casts himself from a precipice into a yawning abyss, he closed the eyes of reason and put a veil between them and his peril
[/i] . Appian followed the same lines.

But, here, it's Suetonius that will give you the answer.