The Calouste Gulbenkian Collection reached Portugal between 1959 and 1960, and was open to the public at the Palace of the Marquises of Pombal, Oeiras, until the Calouste Gulbenkian Museum opened in Lisbon on 2 October 1969.

On 15 November 1967, unexpected flooding hit the storeroom at the Pombal Palace, damaging many works from the collection, specifically a large number of western manuscript books. These were subsequently restored at the Gulbenkian Museum workshop.

At the time, the Book of Hours of Afonso I d'Este was being exhibited in the palace galleries and was therefore not affected by the flooding. It remains in perfect condition, maintaining the original Renaissance brilliance and the freshness of the illuminations by Matteo da Milano.