The painting, of two women killing a man, that is said to be the boys' favourite, is titled "Judith beheading Holofernes" and was painted in 1612 by Italian artist Artemisia Gentileschi (1593-1652).
The location used for the school, the Mansion of Lyme Park in Cheshire, was also used as Mr. Darcy's estate, Pemberley, in the 1995 BBC series starring Colin Firth.
The inside of the school used in the film is Marchmont House, the outside is Manderson House, both on the outskirts of Duns in the Scottish Borders.
Isaac Hempstead Wright (Tom Hill) and Joseph Mawle (Edward Judd, the groundskeeper) also star together in Game of Thrones (2011) as uncle and nephew. Mawle portrayed Benjen Stark, brother of Ned Stark, while Wright portrays Bran Stark, Ned Stark's son. In addition, Ian Hanmore (Albert Flood) portrays Pyat Pree.
The music of the hymn "Be Still, My Soul" the boys and the congregation are singing, is "Finlandia" by Jean Sibelius.