Konrad Kyeser

Konrad Kyeser, illustration on his Bellifortis manuscript (Cod. Ms. philos. 63)

Konrad Kyeser (26 August 1366 – after 1405) was a German military engineer and the author of Bellifortis (c. 1405), a book on military technology that was popular throughout the 15th century. Originally conceived for King Wenceslaus, Kyeser dedicated the finished work to Rupert of Germany.

A native of Eichstätt, Kyeser was trained as a physician and lived at the court in Padua before he joined the crusade against the Turks which ended in disaster at the Battle of Nicopolis in 1396. Kyeser lived in exile in a mountain village in Bohemia during the reign of Sigismund in 1402 to 1403.