The Venetian ambassador in Rome, Girolamo Zulian, confident in the abilities of the young Canova, decided to commission a sculpture in 1781, leaving him free to choose the subject to be represented. It seems that at first the artist had thought of a group with Theseus fighting against the Minotaur, but that soon, on the advice of the most influential neoclassical painter then present in Rome, the Scottish Gavin Hamilton, changed the subject into the most quiet rest of the hero sitting on the defeated monster. For the originality of the mythological theme in sculpture, Canova was inspired by the observation of several ancient marbles (including the sleeping Faun of the collection by Vincenzo Pacetti and the Hermes of Naples) for the figure of Theseus and a Pompeian fresco for the Minotaur. For the figure of the mythical Athenian king, Canova was perhaps also inspired by the Ares (now identified as Achilles) of the Ludovisi collection and by a Hercules who had admired in the gallery of Palazzo Altemps.
Even in the figure of the Minotaur, in order to get closer to the classical ideal, he refused any form of descriptive realism, refusing to follow the advice of those who suggested that he represent the body of the monster, all covered with hair. The work was greeted with authoritative consensus. The success decreed by this first Roman work denounced the changed aesthetic orientation assimilated by Canova, now turned to the study and reflection on the ancient; but above all it sanctioned the new disposition of the artist eager to renew, with that flawless silhouette, the emotional suggestions and the seduction that the statuary of the ancients had exercised on scholars and collectors throughout Europe. Symbol of the victory of human intelligence and courage over brutality and animal ferocity, Theseus represents the first, significant step towards the formal conquest of that "noble simplicity and quiet greatness" that Winckelmann, Neoclassicist theorist, had identified as a beautiful ideal.