Plutarch (/ˈpluːtɑːrk/; Greek: Πλούταρχος, Ploútarkhos, Koine Greek: [plǔːtarkʰos]; later named, upon becoming a Roman citizen, Lucius Mestrius Plutarchus (Λούκιος Μέστριος Πλούταρχος);[a] c. AD 46 – AD 120) was a Greek biographer and essayist, known primarily for his Parallel Lives and Moralia. He is classified as a Middle Platonist. Plutarch's surviving works were written in Greek, but intended for both Greek and Roman readers.

Important works;

-Parallel Lives

Plutarch's best-known work is the Parallel Lives, a series of biographies of famous Greeks and Romans, arranged in pairs to illuminate their common moral virtues and vices. The surviving Lives contain 23 pairs, each with one Greek Life and one Roman Life, as well as four unpaired single Lives.
As is explained in the opening paragraph of his Life of Alexander, Plutarch was not concerned with history so much as the influence of character, good or bad, on the lives and destinies of men. Whereas sometimes he barely touched on epoch-making events, he devoted much space to charming anecdote and incidental triviality, reasoning that this often said far more for his subjects than even their most famous accomplishments. He sought to provide rounded portraits, likening his craft to that of a painter; indeed, he went to tremendous lengths (often leading to tenuous comparisons) to draw parallels between physical appearance and moral character. In many ways, he must be counted amongst the earliest moral philosophers.

-Moralia

The remainder of Plutarch's surviving work is collected under the title of the Moralia (loosely translated as Customs and Mores). It is an eclectic collection of seventy-eight essays and transcribed speeches, including On Fraternal Affection—a discourse on honour and affection of siblings toward each other, On the Fortune or the Virtue of Alexander the Great—an important adjunct to his Life of the great king, On the Worship of Isis and Osiris (a crucial source of information on Egyptian religious rites), along with more philosophical treatises, such as On the Decline of the Oracles, On the Delays of the Divine Vengeance, On Peace of Mind and lighter fare, such as Odysseus and Gryllus, a humorous dialogue between Homer's Odysseus and one of Circe's enchanted pigs. The Moralia was composed first, while writing the Lives occupied much of the last two decades of Plutarch's own life.