"The Book of Hours - a volume of psalms, prayers and a calendar - was commissioned by Duke Galaezzo Maria Sforza of Milan for his wife, Bona of Savoy, in 1490. The Duke wanted the best craftsmanship and turned not to Leonardo (Ed: i.e. Leonardo de Vinci), who had recently painted his Virgin on the Rocks altarpiece in Milan, but to the celebrated miniaturist Giovan Pietro Birago.

Birago was paid 500 ducats - five times the fee Leonardo received for the altarpiece - and produced a book of more than 350 pages, including 64 full-page miniatures and 140 text pages filled with small miniatures and margins bursting with Renaissance ornament.

Birago also left behind a letter to Bona complaining that as he was completing his task one Johanne Jacopo, a friar from the Convent of San Marco in Milan, stole 28 of the illuminated pages, including all 12 of the "calendar illuminations", each one illustrating a month of the year. .....With each page measuring 4.3 inches by 3.6 inches, they would easily have been slipped under his habit.

Margaret of Austria inherited the book in 1504. She commissioned the Flemish artist Gerard Horenbout to paint 16 new miniatures, filling some of the gaps left by the theft.

The hybrid book was eventually presented to the British Museum - before the library's creation - by the Scottish collector and landowner John Malcolm of Poltalloch in 1893.

Forty years later, rumours began that one of Birago's stolen illustrations may have survived and was in the hands of a private owner.

The British Museum put the word around that it was keen to acquire it and in 1941, the illumination, The Adoration of the Magi, was donated anonymously.

In the 1960s, there were more rumours that two of the calendar illustrations had survived and in 1984, the new British Library tracked down one, a spring scene depicting May and bought it from the late Martin Breslauer, a New York dealer.

Then a year ago, a Chicago dealer, Sandra Hindman, reported that she had the hunting scene, Birago's illustration for October. She had acquired it from Mr Breslauer, who had purchased it from an Italian dealer in the 1960s."

The library raised the ?191,000 (thanks largely to an emergency grant of ?131,000 from a charity) in order to buy scene directly from Hindman.