Sforza Hours
The book remained in an unfinished state for 30 years until Margaret of Austria, Regent of the Netherlands, commissioned its completion in 1517–20 from the artist Gerard Horenbout.
It provides a unique example of an early sixteenth-century Northern Renaissance illuminator's response to Milanese art of the late Quattrocento.
Completion of the book was probably abandoned in 1494 when Bona found herself excluded from power by her brother-in-law, Ludovico Sforza, following the death of her son Gian Galeazzo.
[2] Bona of Savoy and Margaret of Austria were identified as the original owners of the book in 1894 from mottos and inscriptions on various folios.
In the letter, Birago claims that a friar, Fra Johanne Jacopo, had stolen the incomplete Book of Hours.
[4] Margaret, who was the daughter of the Habsburg Maximilian I, Holy Roman Emperor, moved to the Netherlands in 1506 as Regent for her nephew Charles and there she became one of the great patrons of the Northern Renaissance (the Arnolfini Portrait was a notable item in her collection).
These pages were executed in a rounded Italian Gothic hand in an attempt to imitate the book's original script.
[6] There is a portrait of Charles, wearing the chain of the Order of the Golden Fleece, in one of Horenbout's text illustrations dated 1520.
It is therefore widely believed that Margaret gave the Sforza Hours to her nephew as a gift on the occasion of his coronation as Charles V, Holy Roman Emperor.
[9] In 1956, Birago was confirmed as an original artist of Sforza Hours following the discovery of his signature on the frontispiece of Giovanni Simonetta's Sforziada from 1490.
[14] Horenbout's additions to the Sforza Hours demonstrate a deliberate attempt to adapt his own style to a more Italianate one that would complement Birago's existing illuminations.
Horenbout's Saint Mark (fol.10.v), for example, has similar features to Birago's St Matthew (fol.7.r), such as the Italian Renaissance architectural setting and the scroll in the foreground.
[24] These prayers contain a full-page miniature of the Mass of St Gregory (fol.167.r) and 5 decorated borders by Birago depicting Passion scenes.
[29] There is also one decorated border by Birago (fol.213.r) to which Horenbout added the portrait of Charles V.[30] More than half the folios of the Litany are replacements.
It includes one miniature, the Procession of St Gregory (fol.236.r), and 8 decorated borders by Birago depicting Old Testament heroines and female saints.
