Life Theodosius of Alexandria (Θεοδόσιος ὁ Ἀλεξανδρεύς) was a Greek grammarian active in the late fourth and early fifth centuries CE. He worked within Alexandria’s scholarly tradition, but no specific biographical details about his life or education survive [1][2][3].

Works His principal work is the Κανόνες περί κλίσεως ὀνομάτων καὶ ῥημάτων (Canones peri kliseōs onomatōn kai rhēmatōn), a systematic treatise on the inflection of Greek nouns and verbs. This grammatical handbook was preserved and used extensively in later Byzantine education [1][2][3].

Significance Theodosius’s Canones is a key work of Late Antique Greek grammatical scholarship. It provided a concise set of morphological rules that served as a standard textbook for centuries. Its influence endured through the medieval period, with later grammarians such as Maximus Planudes compiling and commenting on its precepts [1][2][3].

Sources 1. Perseus Digital Library (Tufts University): http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0057:entry=qeodo/sios 2. Oxford Research Encyclopedia of Classics (Oxford University Press): https://oxfordre.com/classics/view/10.1093/acrefore/9780199381135.001.0001/acrefore-9780199381135-e-6337 3. Encyclopædia Britannica: https://www.britannica.com/biography/Theodosius-of-Alexandria