Sappho (Σαπφώ, c. 630-570 BCE) was the Greek lyric poet of the island of Lesbos — Plato called her "the Tenth Muse." Her poems of love and longing survive only in fragments but defined Western lyric poetry.
The words "lesbian" and "sapphic" derive from her name and island.
Sappho reduces to seven — the number of the Tenth Muse.