Giovanni Bononcini's fame is generally put in connection with his activity as an opera composer and major representative of the galant style. He, however, was one of the most prominent cello virtuosi of the 18^th century; in his cello treatise (1741), Michel Corrette even considered Bononcini the "inventor" of the modern cello. Despite Bononcini's significant role in the history of the cello, only one sonata for this instrument has been tentatively attributed to him thus far. A miscellaneous manuscript that I have discovered, today held in the library of Montecassino (Italy), includes two "Sinfonie per violoncello del Sigr. Giovanni Bononcini." The manuscript bears the date 1699 and some indications point almost certainly toward Neapolitan origins for this source. I have recently published the two sonatas by Bononcini (SEDM, 2019), and in this paper I will discuss their characteristics, the possible date and circumstances of their composition, and the significance these two works have in the history of the development of the cello in the 18^th century.