historical evidences of such an institution in Sagres during the presence of Prince Henry. The School of Sagres is a later "production" from some authors 
Therefore, one must understand the idea of “School of Sagres”, not in the physical and institutional sense, but as a  to have the idea for it.

 The recent Peter Russell book Prince Henry the Navigator: A Life 
presents good historical evidence that Henry was indeed instrumental in the conquest of Ceuta, and not simply part of the "operation".