Johann von Geyso | |
|---|---|
 Johann von Geyso | |
| Born | 1593 Borken, Holy Roman Empire |
| Died | 1661 |
| Allegiance |  Sweden  Bohemian Estates Protestant Union  Denmark  Landgraviate of Hesse-Kassel |
| Rank | General-Lieutenant |
| Battles / wars | Ingrian War |
Johann von Geyso (1593 – 1661) was a German nobleman and General-Lieutenant, who fought during the course of the Thirty Years' War. After studying in a Dutch military academy, Geyso fought as a mercenary in the armies of Sweden, Bohemia, Denmark and the German Protestant Union. In 1628, having gained significant experience in warfare he returned to his native Hesse-Kassel which he served until the end of the Thirty Years' War, reaching the rank of commander in chief of the Langraviate's forces and becoming ennobled.