WILLIAM IV., landgrave of Hesse (1532-1592), was the son and successor of the landgrave Philip the Magnanimous. He took a leading part in safeguarding the results of the Reformation, endeavouring to unite all sections of Protestantism against the Catholic reaction. As ruler he displayed common-sense and toler ance ; patronized art and science; placed the finances of his country on a sound basis and secured it against subdivision by a law of primogeniture. He was chiefly famous, however, as a pioneer in
astronomical research.
See R. Wolf, "Astronomische Mittheilungen," No. 45 (Vierteljahrs schrift der naturforschenden Gesellschaft in Zurich, 1878).