Earlier in his career, Long was particularly influenced by Spanish art and culture, as evidenced in A Question of Propriety (1870). But from the mid 1870s he specialized mainly in Oriental and Biblical subjects.
After his Babylonian Marriage Ceremony sold for 7,000 guineas in 1875, Long’s work commanded very high prices. But, as Christopher Wood observes succinctly, “[A]fter his death, Long’s reputation did not last.”
Both A Question of Propriety and Queen Esther were commissioned from Long for the NGV by Alfred Taddy Thomson.
For Long, see Wood, Victorian Painters (1995), vol.I, p.322 (quoted), and vol.II, p.303 (reproducing the Babylonian Marriage Ceremony, now in Royal Holloway College, Egham); Wood adds that the latter work sold at Christie’s for 6,300 guineas in 1882, “a Victorian saleroom record for the work of any living English artist.” See also AKL 85 (2015), p.228 and Bénézit 8, pp.1198-99 (both mentioning the NGV paintings)