French Baroque composers, like their counterparts all over Europe, regarded the bass viol, the cello, the bassoon and, in some circumstances, the double bass as suitable sustaining continuo instruments. The choice of one or another, or a combination, depended no less upon circumstances than it did on the desire for a specific stylistic nuance or timbre. In this paper I propose to examine the evidence – in memoirs and other accounts, and in manuscript and printed scores – that documents the rise and decline of the bass viol and the emergence of the cello as a chamber music instrument. The nature of the musical evidence is often contradictory in itself, but ultimately it is indicative of a larger process, of which the use of the viol and the cello were a significant part: the assimilation of Italian genres into the French musical idiom.