The scanty extant evidence for the life of Magnes, who is linked with Chionides as one of first two real comic writers of Athens, points clearly to the conclusion that his career as a true playwright falls later than 460 B.C. Suidas (s.v.) says that when a young man he attacked Epicharmus, then in his old age. But as Epicharmus seems not to have died before 450 B.C., this statement fits in well with our other data. Aristophanes in his Knights (424 B.C.) speaks of Magnes' death at an advanced age as a recent event. From these facts, combined with the oft-cited passage of Aristotle, it has been reasonably inferred that he flourished about the 80th Olympiad, 460 B.C. and onwards.
According to Suidas he was a native of Icaria in Attica, or of Athens herself. The most important evidence for his literary career is the passage just sited from the Knights of Aristophanes. From this and the valuable scholia on it we learn that he wrote plays called the Harpers (Barbatistai), the Maggots (Psenes), the Birds and the Frogs, that with the coming of his grey hairs he lost his once great popularity, which had enabled him to set up many trophies for the victories won by his choruses, and that he was hissed off the stage when he had lost his capacity for scurrilous jesting. From the last-named of his plays just cited it seems that Aristophanes borrowed at least the titles, if not the themes, for two of his own most famous works.
According to Suidas, Magnes exhibited nine plays and gained two victories, which is at variance with the statement of Aristophanes that he had won many times. On the other hand the anonymous writer on Comedy avers that he won eleven victories, but that none of his plays were preserved, though nine were falsely ascribed to him. As Magnes is the earliest comic poet of whom any victories are recorded, and as we are told by Aristotle that 'it was only at a late date that the comic poet was furnished by the archon with a chorus', and as a victory implies a public contest, and that in turn implies a chorus at the public expense, the custom of furnishing comic choruses must be assigned to a period posterior to 460 B.C.