Incredible. I grew up in Italy, studied Latin, and never heard of TWO Senecas. The most famous one is the Younger Seneca. The Elder was simply his father.
From wikipedia:
Lucius Annaeus Seneca (54 BC – c. 39 AD), known as Seneca the Elder.
Lucius Annaeus Seneca (c. 4 BC – AD 65),[1] also known as Seneca the Younger, is the one that married to Pompeia Paulina.
Both born in today's Spain (Hispania, then a Roman province), but both educated in Rome.
From the Wikipedia's page on Seneca the Younger [0]:
In AD 65, Seneca was caught up in the aftermath of the Pisonian conspiracy, a plot to kill Nero. Although it is unlikely that Seneca was part of the conspiracy, Nero ordered him to kill himself. Seneca followed tradition by severing several veins in order to bleed to death, and his wife Pompeia Paulina attempted to share his fate.
Also interesting about Seneca the Younger [1]:
His life took a sharp turn in 41 A.D. once Claudius became the emperor as he exiled Seneca to the island of Corsica on the premises of supposed adultery with Julia Livilla, the emperor’s niece and Caligula’s sister. During his exile, he wrote a letter to his mother consoling her during his exile. Eight years later, in another twist, Agrippina, mother of future emperor Nero and wife of Claudius secured permission for Seneca to return and for him to become her son’s tutor and adviser. Nero later became one of the most notorious and tyrannical emperors in the history of the Roman Empire raising even more questions about Seneca’s character. Not surprisingly, Seneca’s wealth came largely while in service to Nero.
[0]: https://en.wikipedia.org/wiki/Seneca_the_Younger#Death
[1]: https://dailystoic.com/seneca/