Ecl. 1 was written B.C. 41 as a thanksgiving to Augustus (see [p. 150]).
Ecl. 2 cannot be earlier than the end of 43 when Pollio was made governor of Gallia Transpadana, and possibly should not be put earlier than the summer of 42. The poem is written on his favourite slave Alexis (see Serv. ad loc.).
Ecl. 3 was probably written soon afterwards. Virgil refers in l. 84 to his intimacy with Pollio,
‘Pollio amat nostram, quamvis est rustica, Musam.’
Ecl. 2 and 3 are earlier than 5. Cf. 5, 86-7,
‘Haec nos “Formosum Corydon ardebat Alexim,”
haec eadem docuit “Cuium pecus? an Meliboei?”’
Ecl. 4. The date is clear from l. 3,
‘Si canimus silvas, silvae sint consule dignae.’
It must have been written in 40, when Pollio was consul. This eclogue, which in the Middle Age was believed to be a prophecy of the Messiah’s coming, cannot be satisfactorily explained as referring to Pollio’s son Saloninus, or to the expected child of Augustus, Julia.
Ecl. 5. Spohn’s view is highly probable, that it was written for the first celebration of Caesar’s birthday in July, 42.