Painted at the commission of Urban VIII's nephew Taddeo Barberini, the two large canvases, The Massacre of the Niobids and The Hunt of Diana were recorded in 1648-49 as hanging in his residence in the Via dei Giubbonari. Later, between the end of the seventeenth and beginning of the eighteenth centuries, they were transferred to the Palazzo Barberini alle Quattro Fontane, where they were definitively recorded in 1817.On the basis of payments to Camassei recorded in the Barberini account books for the Hunt of Diana, the paintings can be dated to 1638-39. It was Cardinal Bentivoglio who originally introduced the artist to Prince Taddeo, who became the artist's patron and protector.Many of the details of Camassei's treatment of this rare subject derive from a famous precedent, the Hunt of Diana that Domenichino executed in 1617 for Scipione Borghese. Nevertheless on a stylistic level Camassei detaches himself from his model, working in a manner that clearly shows the influence of the Roman neo-Venetian trend of the 1630's. Poussin was the most authoritative representative of this movement, and indeed the figure reclining at the left of Camassei's Massacre of the Niobids seems to derive directly from a counterpart in Poussin's Death of Adonis. The figures in Camassei's painting, with their sculptural quality, have also been connected to a relief by Perrier at the Villa Medici.The dramatic narrative of the Niobids, in which the mortal Niobe is punished for insulting the goddess Latona, comes from Ovid's Metamorphoses. When Niobe boastingly compared her seven offspring to Latona's mere two, the angry goddess retaliated by sending her children Apollo and Diana to slaughter Niobe's brood. With his compositional and formal choices, Camassei treats the scene almost like a genre picture, depriving it of some of its inherent high drama.