Verses 22 and 23 of the Theognidea assert that they are “the words of Theognis the Megarian, known by name among all men.” This assertion provides most of the available information about him. No ancient biography survives, and perhaps none ever existed. The dates and even the place of his origin are disputed. Because Plato makes him a citizen of the Megara in Sicily, this view has had its adherents; most often, however, he is associated with Megara on the Isthmus of Corinth, near Athens.
The few historical allusions in the Theognidea span a period from the seventh to the fifth century b.c.e. Passages that seem to anticipate a tyranny at Megara were presumably composed before the actual tyranny of Theagenes, which perhaps began about 630; the threat from the Medes in verses 764 and 775 should be the invasion of Xerxes in 480. Some medieval sources place the floruit of Theognis between 552 and 541 b.c.e. The tenth century lexicon, the Suda, gives the fifty-ninth Olympiad, 544 to 541, as his floruit. The dates of 544 to 541 and the 630’s have gained the most favor. Passages which seem earlier and later than the chosen floruit are explained as anonymous compositions included before about 300 b.c.e. among the genuine poems of Theognis.
Verses 19 to 23 of the passages cited above invite this kind of speculation. Theognis claims to put a sphregis, or seal, upon his words so that it would be obvious if they were stolen. This sphregis is commonly assumed to be the name of Kyrnos, a youth to whom these verses are addressed. Accordingly, the name Kyrnos or his patronymic, Polupaides, in a poem identifies it as genuinely by Theognis. Thus, of almost fourteen hundred verses attributed to Theognis, about one-fourth are usually considered genuine, with Theognis’s name attached to the whole because of the predominance and prominence of the Kyrnos poems.
A radically different view sees the name of Theognis as generic, traditionally associated with Megarian gnomological elegiac poetry. From this perspective, the chronological range of the poetry has no significance; the poetry was composed over time. The sphregis becomes the message of the poetry, the traditional code of behavior for the aristocracy.