Aelius Herodianus was a Greek scholar and grammarian who lived and worked during the 2nd century CE under the Roman Empire. He was the son of the famous grammarian Apollonius Dyscolus and was likely born and educated in Alexandria, Egypt. He later moved to Rome, where he found favor at the imperial court of Emperor Marcus Aurelius.
Herodian was an exceptionally prolific writer, credited in antiquity with over fifty works. However, none of his writings survive in full today; they are known only through fragments, summaries, and quotations in later texts. His most important work was a massive, 21-book treatise titled On General Prosody, which systematically detailed the rules for accenting Greek words. He also wrote on subjects like peculiar word usage, rhetorical figures, orthography, and syntax.
His historical importance lies in his role as a systematizer of Greek grammar. According to modern scholars, his work on prosody became the standard reference on Greek accents for centuries. Although his original texts are lost, his influence was preserved because later Byzantine grammarians and lexicographers relied heavily on his research, quoting and summarizing it in their own compilations. Alongside his father, Herodian is considered a leading figure in the high point of ancient grammatical science.