The average blade length of a long sword is around 110 centimetres (3 feet and 7 inches), and the weight is usually between 1.2 and 1.8 kilograms (2.6 to 4.0 pounds). The actual size and weight of a long-sword would depend on personal preference and build of the wielder.
The way of fighting with the long-sword differed from one handed types in that a shield could not effectively be used. This meant an increased emphasis on blade parries and prioritising defense of areas of the body with less armour protection. Yet a typical longsword doesn't require two hands on the handle all the time, giving the possibility of using the off-hand (left hand for right-handers) for punches, grabs, and throws.
While a living tradition of longsword fighting has not survived to our day, manuscripts written by the masters of the art still exist. Possibly the most famous of these treatises are Fiore dei Liberi's "Flos Duellatorum" (1410), Hans Talhoffer's "Alte Armatur und Ringkunst" (1459), and Filippo Vadi's "De Arte Gladiatoria Dimicandi" (1485). Efforts to revive the art are made throughout Europe, and progressing well.
Historically, there seems to have been some confusion as to the difference between what was a long-sword and what was a bastard-sword. Usually they are of a comparable size, and can be used in a similar fashion. As time wore on, bastard-swords came to replace long-swords, as their generally more sharply tapered blades and distinctly rhomboid cross sections were better suited for defeating the increasing armour protection worn on the battlefield. In practice, the words are used as synonyms.
See historical fencing.