The triptych represented by the great Greek tragedians - Aeschylus, Sophocles and Euripides - together with the legendary contents of Roman Archaic dramatic verse - including Ovid's Heroides - make up Seneca's main source of inspiration for his nine tragedies. These works represent our only surviving example of complete Roman tragedies. Seneca chose amongst his various sources those plots, figures and themes that could express more vividly the results of his study of human psychology and his moral as well as philosophical convictions. His works which are all highly original in style were destined to be read out in public. Therefore the language he chose is bombastic and depicts vividly the vibrant passions that move his characters, all involved in complex family dramas which urge them to commit the most horrible crimes.

In the early Middle Ages Seneca's tragedies were held as a series of moral treatises thus providing maxims for Christian education. Naturally at the time all elements that could lead back to Seneca's Stoicism were censored.

At the beginning of the 14th century Cardinal Niccolò da Prato (ca. 1307-1317) commissioned to the Dominican friar Nicholas Trevet the composition of a commentary to Seneca's tragedies that would enable readers to understand the complexity of their verse and mythological allusions. At the same time, in the first quarter of the 14th century, the circle of the so-called Pre-Humanists active in Padua discovered the importance of these tragedies as a literary genre in themselves. One of these Pre-Humanists, viz. Lovato Lovati, found in the Abbey of Pomposa the oldest known complete collection of Seneca's tragedies, i.e. the so-called Etruscus codex that can be dated to the 11th/12th century. The tragedies contained therein follow this order: Hercules furens, Troades, Phoenissae, Medea, Phaedra, Oedipus, Agamennon, Tyestes, Hercules Oeteus.

Thus, in the 14th century Seneca's tragedies gained a new span of life and were copied in many manuscripts, in some cases real luxury books. One of the major features of this production is represented by the richness of the decoration which comprises miniatures illustrating the most important scenes. Medieval religious drama was definitely forgotten and all over Europe Seneca's tragedies inspired the work of modern tragedians.

Traditionally also Octavia, a tragedy of Roman inspiration not contained in the Etruscus manuscript, has been ascribed to Seneca. Here Nero repudiates his wife Octavia, daughter of Claudius and Messalina, in order to marry Poppea. Although the people rebelled in aid of Octavia Nero, after suffocating the revolt, has her sent to the island of Pandataria where she is condemned to death.