For the subject of this fresco see Apollodorus, 'Library' (3: 10). Apollo slew the one-eyed race of giants, the Cyclops, because they had provided Zeus with the thunderbolts which killed his son, Aesculapius.
The fresco (transferred to canvas) comes from a series painted in the Stanza di Apollo in the garden pavilion at the Villa Aldobrandini, Frascati.
The classical scene was painted as a trompe-l'oeil tapestry, probably by assistants. Domenichino's participation in the painting was likely limited to the portrait of the dwarf in chains at lower right. This member of the Aldobrandini household was depicted in this derisive fashion for his insolence.
An autograph life study of the dwarf (Windsor, Royal Collection) is the only drawing to survive for this composition.