The Greek author Theocritus (ca. 310-ca. 245 BC) is credited with being the first and greatest pastoral poet. He expressed great delight in nature and rural life.

The best source for the biography of Theocritus is his own poems. He was a native of Syracuse who was familiar with Croton and Thurii in southern Italy, the island of Cos, Miletus, and Alexandria. He was born by at least 310 B.C., and probably earlier. His parents were Praxagoras and Philinna (who was originally from Cos). Theocritus was a pupil of Philetas of Cos, as it is conjectured that Ptolemy Philadelphus also was. Theocritus was a friend of Callimachus, of the physician Nicias of Miletus, and of King Hiero of Syracuse. Theocritus's life has been described as falling into four divisions: the Coan, the Sicilian, the Alexandrian with a second Coan residence, and after 270 B.C.

All of Theocritus's work is not pastoral; it is as an idyllist that he is known because with great skill he established the genre and its characteristics: the use of the dactylic hexameter, the Dorian dialect, familiar forms (dialogues of herdsmen, their recitations and rivalries), and the themes of unhappy love, death, or absence of friends.

Not all of Theocritus's works have survived. The Coan period saw the production of the bucolic poems (Idylls VII, III-VI, VIII, X, XI, I). The Sicilian period saw only Idyll XVI. Possibly Idylls XXV and XXIII belong to this period. Disappointed in apparent lack of success in Sicily, Theocritus went to Egypt in 274, where he wrote Idylls XV and XVII, probably the Berenice (lost), Hymns XXII and XXIV, and Epyllion XIII. His works included Daughter of Proteus, Hopes, Hymns, Heroines, Funeral Laments, Elegies, lambics, and Epigrams. Of these, 26 epigrams and 30 idylls are preserved.

Theocritus is a master of his art. His style is polished, natural, and graceful. The poems were called idylls (the Greek eidyllia) because they present fresh little pictures of rustic life, reflecting the simple life and conversation of the herdsman of Sicily, southern Italy, and Cos.