The arbalest (also arblast) was a late variation of the crossbow coming into use in Europe during the 12th century. A large weapon, the arbalest had a steel prod ("bow"). Since an arbalest was much larger than earlier crossbows, and because of the greater tensile strength of steel, it had a greater force. The strongest windlass-pulled arbalests could have up to 22 kN (5000 lbf) of force and be accurate up to 100 m. A skilled arbalestier (arbalester) could loose two bolts per minute.
The term "arbalest" is sometimes used interchangeably with "crossbow". "Arbalest" is a Medieval French corruption from the Roman name arcuballista, which was then used for crossbows, although originally used for types of artillery; Modern French uses the word arbalète, which is linguistically one step further from the stem (disappearance of the s phoneme in the last syllable before t). The word applies to both crossbow and arbalest (the latter may be referred to as a heavy crossbow, but an actual heavy crossbow may not be the same as an arbalest). In some cases, the word has been used to refer to arbalists, the people who actually used the weapon.