The parrying dagger is a category of small handheld weapons from the European late Middle Ages and early Renaissance. These weapons were used as off-hand weapons in conjunction with a single-handed sword such as a rapier. As the name implies they were designed to parry, or defend, more effectively than a simple dagger form, typically incorporating a wider guard, and often some other defensive features to better protect the hand as well. They may also be used for attack if an opportunity arises. The general category includes two more specific types, the sword breaker and trident dagger.
The use of this off-hand weapon gradually fell out of favor as sword fighting evolved into the modern sport of fencing. The use of progressively lighter primary weapons such as the small sword, épée and foil allowed for greater speed since the fencer needed less protection for himself as double hits became more allowed in sport fencing.
Parrying daggers were an important development of the ubiquitous quillon dagger form, appearing in the early to mid-16th century starting with the so-called left hand dagger. Although this is often used as a term of convenience for parrying daggers in general, it also refers more specifically to the earlier and simpler form of the weapon. It had stout quillons (straight or curved) for effective parrying as well as an additional guard in the form of a ring or shell on one side of the quillons where they crossed the grip. In addition to straight blades, there are examples of left hand daggers with wavy blades, those with saw edges and blades that are perforated along the central fuller with small holes, all designed to make the weapon lighter or to aid in defense. This form of dagger largely disappeared in the early 17th century in favor of the much more important main-gauche which was especially popular in Spain and Italy. The triple dagger and swordbreaker were rare and relatively late developments, first appearing around 1600. Parrying daggers were often made en suite, or similar in terms of construction and decorative technique, to the sword with which they were paired as a companion weapon.