A longsword is a sword of a design popular in the late Medieval and early Renaissance eras in Europe. This design is also sometimes referred to as a “greatsword,” and a number of examples can be seen on display in museums dedicated to swords and the history of combat. Numerous depictions of the longsword in action can also be seen in works of art from this period, displaying the array of longsword fighting styles and techniques used by various groups.

As the name would seem to imply, this sword is long, but that's not the only distinguishing feature. It also has a distinctive cross-shaped hilt, and a double-edged blade. The entire design is quite heavy, and designed to be wielded with two hands in most cases. Classically, the hilt has a long handle so that there is room for both hands, and the base of the blade is blunt, allowing people to use a longsword for half-sword fighting, in which one hand is held on the blade for balance and control.

This long, heavy design was customized for chopping and slicing cuts meant to kill or severely disable the enemy. A strong soldier could severely damage or destroy armor with a longsword, and the point of the sword could be used in thrusting jabs designed to get underneath armor plating. Every part of the longsword is designed as a weapon, from the hilt, which can be used for blunt impact injuries, to the very sharp tip.

Originally, these swords had very basic diamond-shaped blades which tended to be thin. Over time, more complex designs which included channels in the center of the blade were developed, and the overall thickness began to increase. The longsword became a formidable weapon as the use of armor increased, since sword makers had to respond to the rise of armor with a weapon which could cope with it. Training with a longsword required a great deal of strength and control to ensure that the blade was used effectively.

Although longsword matches are sometimes described as clumsy and lacking in form, these swords could actually be used very effectively and gracefully, with the proper training. People usually started with wooden practice swords to learn proper form and get accustomed to the length, moving on to metal swords as they learned the basics so that they could familiarize themselves with the weight. A number of swordfighting techniques could be used with this type of sword, and a skilled fighter come come up with innovative variations on basic techniques to make the longsword a very useful weapon.