Black Hours (Black Prayer Book) of Galeazzo Maria Sforza
Horae ad usum Romanum (Codex Vindobonensis 1856)
Miserere mei, Deus, secundum magnam misericordiam tuam.
Our renderingHave mercy on me, O God, according to your great mercy.
What it is
One of only a handful of surviving Books of Hours written on dyed black vellum, this manuscript was likely commissioned by Charles the Bold of Burgundy in Bruges c. 1466–1477 and subsequently entered Sforza possession through diplomatic or gift channels before passing via Bianca Maria Sforza's dowry to Emperor Maximilian I in 1493. Its texts — canonical hours, psalms, penitential prayers, and miniatures in silver and gold against black — follow the Roman rite, and the exceptional medium transforms the entire codex into a visual meditation on mortality and grace. The use of black parchment, a material extravagance available only to the wealthiest patrons, gave the book an immediate penitential resonance that its Burgundian and Italian owners would both have recognised. Now held at the Österreichische Nationalbibliothek in Vienna as Codex Vindobonensis 1856.
Why it still matters
Its psalms and canonical hours are fully continuous with today's Roman Liturgy of the Hours; the penitential framing of the manuscript — prayer surrounded by darkness and lit with gold — offers a powerful visual grammar for Lenten or evening prayer today.
Kept alongside
Hours of Gian Galeazzo Visconti (Visconti Hours)
Officiolum Vicecomitis (Hours of Gian Galeazzo Visconti)
Begun in the late 1380s–1390s for Gian Galeazzo Visconti, first Duke of Milan, and completed under his son Filippo Maria Visconti around 1430, this two-volume masterpiece of Italian illumination contains the Hours of the Virgin, Hours of the Cross, Hours of the Holy Spirit, Penitential Psalms with litanies, Office of the Dead, and suffrages to saints, all following Roman liturgy. Giovannino dei Grassi's exquisite naturalistic marginalia and Belbello da Pavia's intense Gothic figural work across two generations make it the most ambitious manuscript project of the Visconti court and a foundational document of north Italian Renaissance art. The Sforza dynasty inherited the Visconti duchy through the marriage of Bianca Maria Visconti to Francesco Sforza (1441), and with it inherited the devotional culture this manuscript represented, though direct Sforza use of this specific codex is not positively documented. The manuscript is now at the Biblioteca Nazionale Centrale in Florence (Banco Rari 397 and Landau-Finaly 22).
Hours / Officium Beatae Mariae Virginis of Anna Sforza and Cardinal Ippolito d'Este
Officium Beatae Mariae Virginis (Hours of Anna Sforza / Cardinal Ippolito d'Este)
Produced in Milan around 1491–1500 by the Sforza court illuminator Francesco Binasco, this luxury Book of Hours links the Sforza and Este dynasties through the marriage of Anna Sforza to Alfonso I d'Este in January 1491. Scholarly debate continues over whether it was commissioned by Cardinal Ippolito d'Este — whose cardinal's hat appears in the manuscript — or prepared as a wedding gift for Anna Sforza; the cardinal's hat strongly suggests Ippolito as the primary patron. It contains a Roman-rite calendar, privately ordered prayers of devotion, twelve full-page miniatures of the Virgin and female saints, and 146 historiated initials. Now preserved at the Biblioteca Estense Universitaria in Modena (MS Lat. 74 / alfa Q.9.31), it is a rare documented case of a Book of Hours that bridges the devotional cultures of two of northern Italy's most powerful courts.
Sforza Hours
Horae ad usum Romanum (Sforza Hours)
Commissioned c.1490 by Bona of Savoy, widow of Galeazzo Maria Sforza and former regent of Milan, from her court illuminator Giovan Pietro Birago, this is one of the supreme masterpieces of Italian Renaissance illumination. Left incomplete after a documented theft of folios recorded in Birago's own letter — making it one of the earliest recorded art thefts — it was finished by the Flemish master Gerard Horenbout for Margaret of Austria c.1517–1520, uniting Milanese and Flemish illuminative traditions in a single codex. Its devotional texts include Gospel lessons, the Hours of the Virgin, Hours of the Cross, Hours of the Holy Spirit, the Penitential Psalms, the Office of the Dead, and suffrages to saints. Now held at the British Library (Add. MS 34294), it stands as a monument to the personal piety of a widowed duchess navigating political exile and dynastic loss.