Ridolfo Capo Ferro
Although he may have studied with masters of the German school, his teachings do not reflect perceptible German influence, but instead are in the Italian tradition, with a notable influence from the earlier Italian school of swordsmanship of the 16th century.
"Art and Use of Fencing" 
Capoferro's treatise "Great Representation of the Art and Use of Fencing" was printed by Salvestro Marchetti and Camillo Turi in Siena, and is divided into two parts: Art and Practice.
In the first part, he gives the general principles of swordsmanship and fencing, with the second part of his book covering actual techniques, described in text with accompanying illustrations. His work is interesting in that some methods that he denigrates in his theory he uses in his actions; most notably, he dismisses feints as dangerous or useless (depending upon the situation) and then uses them liberally in various actions in the second part of his book.
The sword that Capo Ferro recommends should be "twice as long as the arm, and as much as my extraordinary pace, which length corresponds equally to that which is from my armpit down to the sole of my foot." For a 6' tall man this would equate to a 4 1/2' long sword.
The book covers the use of single rapier, including basic sword grappling, as well as Rapier and dagger, Rapier and cloak, and Rapier and Rotella, a most unusual combination for the period, though far more common in the tradition of swordsmanship of the 16th century which preceded it. The Rotella is a medium size concave round shield of approximately 60 cm in Diameter with two straps to hold it. Similar metal shields survive, particularly from Spain in this period, though very few from Italy, implying that these shields were made of a perishable material such as wood or leather or a composite of such materials. The manual also includes techniques for fighting against a left-handed opponent.
Ridolfo's book must have been reasonably popular, as it was reprinted several times, although not many of the fencing treatises written in the next generation mention him and those that do are not necessarily complimentary. An interesting example of this is Francesco Alfieri, who, in his 1640 treatise La Scherma, refers to Capoferro as Capo di Ferro (literally: 'Head of Iron'). However, he was strongly praised by later notable swordsman such as Egerton Castle who says in his 'Schools and Masters of Fence (1893)', "...but of all the Italian works on fencing none ever had such a share in fixing the principals of the science as 'Great Simulacrum of the Use of the Sword, by Ridolfo Capoferro", later adding "for once the title of the book fully represented its contents." A later edition of Capoferro's work also incorporated Biblical scenes drawn into the backgrounds of the plates.
While many modern reference books state that rapiers were either blunt on their edges, or only had sharp edges in order to discourage blade grabs because they were not suitable for the cut, it should be noted that nearly 30% of the techniques included in Capoferro's treatise use the cut as a primary or secondary option.
In the fictional work The Princess Bride by William Goldman, Inigo Montoya and The Man in Black duel atop the Cliffs of Insanity where they mention various fencing techniques they have studied, including those of Capoferro.
Capoferro is sometimes called the grandfather of modern fencing. While the style of fencing and techniques covered do vary greatly from the modern sport of fencing, Capoferro laid down excellent key principles and structure in which to learn, as well as in one single outline the perfect lunge, which characterises the modern sport, being one of the earliest sources to do so and certainly the most clearly laid out.
An extensive German Rapier manual published in 1615 by Huesller clearly draws many concepts from Capoferro and Salvatore Fabris, combining their teachings into one system, Huesller even uses one plate (plate 9) out of Capoferro without a single attempt to change it.
Since the middle of the 1990s there has been a huge revival in Historical European Swordmanship, sometimes called HEMA, WMA or historical fencing and numerous clubs are teaching a variety of styles from the earliest known manuscript (i.33, teaching sword and buckler), through the high medieval and renaissance periods up to the western traditions of the early 20th century such as Bartitsu.
Many different styles of rapier tradition are studied today from the Spanish school of Carranza and Thibault, to the early German rapier works of Meyer and the most popular of styles, the Italian Rapier.
Of all the manuals written on Italian rapier combat, by far the two most commonly used by modern practitioners are those of Salvator Fabris and Ridolfo Capoferro.
Spelling of name 
Because there is an apparent space in the name of the author in the original publication, Capoferro is often spelled as two words: Capo Ferro. However, a look at some sources where he is named or listed, such as in the works of other fencing masters (for example, see page 6 of Giuseppe Morsicato-Pallavicini's 1670 fencing treatise), Jacopo Gelli's fencing bibliography, Dr Anglo's book The Martial Arts of Renaissance Europe, the listing of his books in the US Library of Congress, the Latin form of his name over his portrait (Rodulphus Capoferrus), and the spelling of the surname in modern Italy does support that it is one word.
Despite this, other sources of the time such as "Prima [e secundi] parte dell'Historia siciliana (1606)" clearly show the name spelt as two words. Other works such as "Bibliotheca Stoschiana sive Catalogus selectissimorum librorum quos Collegerat Philippvs Liber Baro De Stosch" (1759), have the name hyphenated (Capo-Ferro).
See also 
- Jared Kirby (ed.), Italian Rapier Combat - Ridolfo Capo Ferro, Greenhill Books, London (2004). 
- Nick Thomas, "Rapier The Art and Use of Fencing by Ridolfo Capo Ferro", Swordworks, UK (2007) 
- Tom Leoni, "Ridolfo Capoferro's The Art and Practice of Fencing", Freelance Academy Press, Inc, USA (2011)