Giulio Regondi (1822-1872) was a unique musical figure in that, not only was he an accomplished multi-instrumentalist and composer, but both of his instruments, namely the classical guitar and English concertina, were equally unpopular and unlikely candidates for romantic virtuosity in Victorian era England. It is Regondi's legacy that during his career he was able to champion both instruments and significantly raise their individual reputations. Following Regondi's death the popularity of both instruments declined, and with them, Regondi's own renown. With the recent resurgence of classical guitar music in the 20th century, Regondi's few surviving guitar compositions have been gradually rediscovered and are arguably now more popular and widely played than ever. As the classical English concertina has seen no such revival, Regondi's far larger surviving body of concertina works remain largely neglected. It is the intent of this research project, through transcribing and arranging a selection of these pieces for classical guitar, to reintroduce these works into the public sphere, and grant guitarists access to an under-appreciated body of repertoire from one of their most beloved composers. This thesis aims, through the study of both historical sources and Regondi's guitar compositions and concertina methods, to produce an edition of arrangements that both reflect period performance practices and present idiomatic, playable works for the modern guitarist. The new works will both merge with the existing canon of Regondi's guitar repertoire, whilst also introducing guitarists to a variety of compositional styles and practices previously unobserved in his guitar works. Through the implementation of an aesthetic framework building on the methodologies of Tariq Harb and Evan Hopkins, this thesis will detail each stage of the complex arrangement process involved in such a unique project, and present a detailed guide with which to approach similar projects in the future.