In early-nineteenth-century Rome only Antonio Canova rivaled the sculptor Bertel Thorvaldsen. One area in which the Dane was the acknowledged master was the independent relief; a contemporary critic termed Thorvaldsen the "patriarch of the bas-relief." While these tended to be small scale, compact, and restrained, in emulation of the ancient compositions that Neoclassical artists revered, this one is unusual for its large size, bold plasticity, and sensual subject. The well known myth concerns the centaur Nessus's betrayal of Hercules' trust: charged with carrying Hercules' wife across the river Euenus, the centaur tries to abduct her but is slain by a poisoned arrow shot by Hercules. Against a severe background the sculptor chiseled the dramatic moment when Deianira waves to her husband for help as her abductor twists to kiss her. Thorvaldsen's starting point for the composition is an ancient Roman relief that he knew from an engraving now in the Thorvaldsen Museum, Copenhagen, completed two years after his death to house the collection he gave his native city. A series of drawings shows the artist's efforts to intensify the figures' interaction. This marble was commissioned by Paolo Marulli, brother of the duke of Ascoli, for his residence in Naples, where it joined other Thorvaldsen reliefs.