Among Vivaldis many flute and recorder concertos, two, both for transverse flute, were known until a few years ago only in incomplete form: RV 431 and 432. Both are written in the comfortable and expressive key of E minor, are transmitted in autograph manuscripts and lack their second movement (RV 432 also lacks its third movement). The seemingly enigmatic instruction Grave sopra il libro replacing the second movement has given rise to the most fanciful hypotheses. The discovery in Edinburgh, in 2010, of a concerto for transverse flute in D minor entitled Il gran Mogol suddenly shed light on the situation: this was an earlier version of RV 431, now complete with its middle movement, a Larghetto that is very possibly identical with the one missing in RV 431. ThisGran Mogol, which belonged to Robert Kerr, a Scottish nobleman and amateur flautist, was already known by name to scholars on account of its listing in an eighteenth-century catalogue as part of a set of Vivaldi concertos bearing geographical titles: more recently, there has come to light a letter written by Vivaldi three months before his death in which the composer describes this setin detail. It is very likely that RV 431 and RV 432 belonged to this group of works, the last known collection of its kind in Vivaldis oeuvre. This critical edition places these closely related works side by side for the first time, placing them in their historical context and making them performable through its reconstruction of some lost parts.