Fredrico Fabio Ghisliero was an Italian fencer and soldier who wrote his text Regole di molte cavagliereschi essercitii in 1587.
Some fencing historians have hypothesized that Ghisliero's use of geometry evidences the influence of the Spanish school (La Verdadera Destreza).
Also, Jeronimo de Carranza, the father of the Spanish school, was heavily influenced by Camillo Agrippa's application of geometry to combat in his book, entitled Trattato di Scientia d'Arme, which also incorporated the idea of a circle that encircled both duelists.
He also wrote on the use of the dagger, and the cloak in combination with the sword, which were mainstays of civilian dress, and were often discussed in manuals of the time, especially those related to the Italian school.
He was noted by Luis Pacheco de Narváez, a major proponent of the Spanish school, as being one of ten leading experts on mounted combat in Europe at the time.