English: Alphonso Psalter, belonging to w:Alphonso, Earl of Chester (1273-1284), 2nd son and heir apparent of King Edward I of England, by his wife Eleanor of Castile. At the age of ten, Alphonso was engaged to Margaret, daughter of Floris V, Count of Holland. An opulent psalter was being prepared for the marriage when he fell ill and died a few months before the wedding was to take place. The Alphonso Psalter was completed a decade later when his sister Elizabeth married Margaret's brother, John I, Count of Holland, making the pairing of arms again appropriate. Alphonso's death at Windsor occurred shortly after the birth of his younger brother Edward, who became the eldest surviving male heir of Edward I.