Dionysius of Halicarnassus is a teacher of ancient Greek rhetorical styles. He migrates to Rome around 30 BC, where he remains until his death, writing the Roman Antiquities and teaching the art of rhetoric and literary composition. His aim, both in his work and in his teaching, was to restore the classical Attic standards of variety, invention, and taste, in order to reaffirm the supremacy of Greek as the literary language of the Mediterranean world.

He supported the detailed study of the styles of the best prose writers of the 5th and 4th centuries BC, mainly the Attic orators. His critical essays on them and the historian Thucydides represent an important development from the mechanical techniques of rhetorical handbooks to a more sensitive critique of individual writers. Illustrating his analysis with well-chosen examples, he preserves a number of significant fragments of Lysias and Isaeus.

The essays on these two orators and on Isocrates, Demosthenes, and Thucydides comprise Volume I of this edition. Volume II contains three letters to his students, a small essay on the orator Dinarchus, and his best work, the essay On Literary Composition, which combines rhetoric, grammar, and criticism in a unique way in ancient literature. The Loeb Library also publishes a seven-volume edition of the Roman Antiquities by Dionysius of Halicarnassus, a history from the earliest times to 264 BC.