The archlute, as the name indicates, is a specialized form of lute. This plucked string instrument dates to the 17th century. The archlute was particularly popular during the Italian baroque era, when it was used for both continuo and solo pieces. Handel was among the composers outside Italy who also composed for the archlute.
The instrument evolved as something of a hybrid between the theorbo and the baroque lute. Like the theorbo, the archlute is a very large instrument, with a long neck and two peg boxes. The archlute’s peg boxes are staggered at the end of the neck instead of one being off to the side, as with the theorbo. The archlute’s tonal range is toward the tenor (like the lute), rather than the bass (like the theorbo).