Lucius Annaeus Seneca, or Seneca the Younger, was a Roman philosopher, statesman, dramatist, and humorist.
Born in Córdoba, Spain, he was the second son of Marcus Annaeus Seneca, a wealthy Roman politician known as Seneca the Elder. Seneca's older brother, Gallio, became proconsul of Achaia (where, according to The Acts, he encountered the apostle Paul about AD 52).
Seneca the Younger was a sickly child who was shipped around the Mediterranean for various treatments. After school in Rome, he moved to Egypt for more medical treatment and remained there until he was 35.
After his return to Rome in 31 he established himself as a successful and prominent advocate. However, he lived in turbulent times and like many noted Romans fell foul of the increasingly insane Emperor Caligula. In 37, after a dispute with the Emperor, Seneca was marked down for execution only to have the sentence stayed by the Emperor who believed the sickly Seneca would not live long anyway.
Four years later Seneca again found himself on the end of Imperial wrath. The Emperor Claudius’ wife Messalina, had Seneca banished to Corsica on a charge of adultery with Julia Livilla, Caligula’s sister.  
Seneca spent his exile in philosophical study and began to write the first of his philosophical works.
In 49, Claudius' new wife Agrippina brought Seneca back to Rome to tutor her son Nero. On Claudius' death in 54, perhaps at Agrippina’s hand, she installed Nero as emperor over Claudius' son, Britannicus.
Seneca became one of Nero's advisors and served for eight years from 54 to 62,  Seneca exerted considerable influence over the young Emperor and in concert with the praetorian prefect Sextus Afranius Burrus, conspired to keep Rome calm and well managed. But Nero increasingly began to ignore the advice of his councillors and with the death of Burrus in 62, Seneca finally stepped aside.
For the next three years, Seneca devoted himself to writing and completed a large body of work including philosophical treatise, a satire, nine tragedies and a number of important letters and essays. Many of his works continue to be read and his plays are still produced. Many later playwrights such as Shakespeare, Voltaire and Racine owe something to the influence of Seneca in their works.
In 65, Seneca was accused of being involved in a plot to kill Nero. Although there was scant evidence of Seneca’s involvemen,t his suicide was demanded by the increasingly unhinged Nero. Seneca chose to cut his wrists, but the blood to flow too slowly. He then took poison but it didn't work. In an effort to make the blood flow faster he jumped into a hot bath. According to Tacitus he died  from suffocation from the rising steam.

On the Shortness of Life
Seneca's brand of Stoic philosophy emphasized practical steps by which the reader might confront life's problems. In particular, he considered it important to confront the fact of one's own mortality.
The short essay On the Shortness of Life is one of Seneca’s better known treatise. In De Brevitate Vitae he touches on many Stoic principles on the nature of time, specifically that men waste much of it in meaningless pursuits. According to the essay, nature gives man enough time to do what is really important and the individual must allot it properly.