 Some of Hernández' original manuscripts are housed in the library of the Escorial, but many were lost in the fire of July 17, 1671.In the winter of 1565 through 1576, Hernández made a copy of his work, due to numerous commands by King Philip II.This would later be considered the second version of Natural History due to Hernández's meticulous revisions and edits per the king's request.