The author of the first dictionary in history is ...
Aristophanes from Byzantium
Aristophanes of Byzantium was a Hellenistic Greek scholar, critic and grammarian, particularly renowned for his work in Homeric scholarship. Born in Byzantium about 257 BC, he soon moved to Alexandria. He succeeded Eratosthenes as head librarian of the Library of Alexandria at the age of sixty. As a lexicographer he compiled collections of archaic and unusual words.