sentences:  After the capture of Francis I by Charles V's troops during the battle of Pavia (1525), the two eldest princes, Francis and Henry, were retained as hostages in Spain in exchange for their father.Because the ransom was not paid in time, the two boys (eight and seven at the time) had to spend nearly four years isolated in a bleak castle, facing an uncertain future.Henry found solace by reading the knight-errantry tale "Amadis de Gaula".