The Longest Night is the major holiday of Terre d'Ange. It is celebrated on the winter solstice each year. This tradition predates the arrival of Elua and his Companions, but Elua liked it so much that he adopted the holiday.
D'Angelines typically celebrate the Longest Night by holding masked balls. These are called the Midwinter Masque. The masque at Cereus House is particularly notable. Cereus holds the masque every year and all the other houses of the Night Court go there. Costumes for the masque may vary widely, but households traditionally come dressed as one particular theme. In the Night Court, no contracts are accepted for the Longest Night. The Dowaynes each have tokens to the Midwinter Masque they may choose to bestow upon patrons. The Midwinter Masque at the palace is also quite extravagant.
The holiday centers around celebration of the sun's return, so two people always play the Winter Queen and the Sun Prince at the masque. The Winer Queen appears as an old woman clad in rags, stooped and hobbling with a cane. The Sun Prince, a young man clad all in gold, enters when the horologist calls the hour of the sun's return and all the lights are extinguished. The Sun Prince taps the Winter Queen with his spear and she lifts off her rags, appearing as a young woman. The Sun Prince is associated with sovereignty over the land, so Prince Baudoin de Trevalion's portrayal of the Sun Prince at Cereus's masque was taken as a political statement. Sidonie de la Courcel also dresses as the Sun Prince at the masque in Kushiel's Justice Cereus always provides the Winter Queen for its masque and the Sun Prince is chosen from among the other houses.
Joie, a type of clear cordial similar to ice wine, is drunk on the Longest Night. D'Angelines consume small glasses of it and say to each other, "Joy to you on the Longest Night."
Cassiline Brothers mark the Longest Night by holding Elua's vigil. They spend the entire night meditating in temples of elua.
Longest Nights seen in the series
- The first Longest Night at Cereus House when Phèdre is ten, Baudoin is the Sun Prince
- Melisande Shahrizai contracts Phèdre for the Longest Night and she attends Quincel de Morhban's Midwinter Masque at the end of Melisande's leash, dressed in a sheer gown
- Masque at the palace where Phèdre dresses as Mara and announces that she is now accepting patrons
- Imriel nó Montrève de la Courcel keeps Elua's vigil with Joscelin Verreuil and becomes sick
- Masque at the palace where Imriel, Phèdre, Eamonn mac Grainne and Ti-Philippe Dumont come dressed as Skaldi gods
- Imriel dresses as Diogenes and Sidonie as the Sun Prince, Imriel and Mavros Shahrizai go to the Masque at Cereus House
- In Alba, Imriel celebrates the Day of Misrule on the winter solstice
- Imriel and Sidonie dress as Night and Day, Barquiel L'Envers pays a man to rant at them during the masque and remind the audience of Melisande's crimes
- In New Carthage, Astegal throws a festival on the winter solstice. After the festival, Sidonie observed Elua's Vigil.
- Moirin attends her first Midwinter Masque at the palace. She and Jehanne then go to the Masque at Cereus House.