• charles iii was the king of spain from 1759 to 1788. he was the fifth son of philip v of spain and elisabeth farnese, and he is known for modernizing the spanish economy and implementing important reforms during his reign. charles iii is also remembered for his support of the arts and sciences, and he is credited with establishing the first spanish observatory and botanical garden. he was succeeded by his son, charles iv, who continued many of his father's reforms.