He was born in
Kemnath,
Upper Palatinate (at the time part of the
Electoral Palatinate under
Frederick V) as the son of the superintendent of the
Reformed church there. His family was forced to move away in the wake of the Catholic victory at
White Mountain when Horn was still an infant. In 1635, he visited the gymnasium in
Nuremberg, and in 1637 he was enrolled in
University of Altdorf as a student of theology and medicine. He later worked as a private tutor, in
Gröningen and later in
Leiden, in the
Dutch Republic. In Leiden, he was also enrolled as a student of
Friedrich Spanheim. After a two year's sojourn in England, he returned to Leiden, compiling a history of the events of the ongoing
English Civil War (
Rerum Britannicarum libri VII,
De statu ecclesiae Britannicae hodierno). In 1648, he completed a doctorate in Leiden and refused calls to both
Frankfurt University and
Heidelberg University as professor of theology, instead accepting the position of professor of history, politics and geography at the new
University of Harderwijk, where he became rector in 1652. In 1653, he became professor of history at
Leiden University, a position he held until his death in 1670. In his later life, Horn was also greatly interested in
alchemy. In 1665, he was swindled out of the considerable sum of 5,000
guilders by a fraudulent alchemist. His interest in alchemy als resulted in an edition of
Pseudo-Geber in 1668. From about this time, he also began to suffer from intermittent spells of mental distraction, although he remained a prolific writer until his death. Among his publications, his Latin works on
universal history, intended as a textbook for students, were especially influential (
Historia ecclesiastica et politica,
Arca Noae,
Orbis Politicus,
Orbis Imperans). These works were re-published long after his death in both the Netherlands and Germany. He treated universal history in a modern manner, no longer divided into the history of the
four classical empires (
Assyria,
Persia,
Macedon,
Rome) but based on the concept of
national history, including the history of the peoples of the New World (
De originibus Americanis). He was also one of the earliest historiographers to divide world history into three major epochs, antiquity from earliest times until the
Migration period, the
middle period from the Migration period to the year 1500, and
modern history from 1500 to his own day. His coverage of the Migration period is presented as the history of the "
Scythian" nation, which is divided into
Germans,
Huns and
Slavs. In all his works, Horn presents himself as a pious Protestant and as a patriot of his homeland, considering himself a native of and exile from the
Upper Palatinate (which had been annexed by the Catholic
Duke of Bavaria in 1628). == Works ==