Sophocles (496-406 B.C), a celebrated ancient Greek tragedian, was believed to have been born into a wealthy family and was thought to be highly educated. As a respected public citizen, Sophocles served as a treasurer, as a general, and as a commissioner for the Athenian expeditionary force.
In his career that span over thirty-six years, Sophocles wrote over 120 plays. Only seven plays have survived in complete form, all of which were stored in public archives at Athens (Slavitt X): Ajax, Antigone, The women of the Trachis, Oedipus Rex, Electra, Philoctetes, and Oedipus at Colonus. Next best survived works of Sophocles are the fragments of the Ichneuteu and Epigoni, which were found in 1907, in Egypt and in 2005 by classicists at Oxford University respectively (“Sophocles”, n.d.).
Sophocles is credited for innovations in dramatic structure and creating scenery-painting. He influenced the development of drama by adding a third actor, thereby reduced the importance of the chorus in the presentation of the plot. Sophocles also created greater opportunity for character development and conflict between characters (Slavitt X).
Reference:

Slavitt, David R, and Palmer Bovie. Sophocles,1 Ajax, Women of Trachis,Electra,Philoctetes. Philadelphia:University of Pennsylvania Press, 1998.
“Sophocles.” Wikipedia, https://en.wikipedia.org/wiki/Sophocles