 Complete the following phrase:  This independence was utilized by Roger and his successors, who henceforth played a crucial role in the internal feuds and plots of the Principality. Thus, faced with the repeatedly manifest inability of the Naples-based Angevin Princes to defend the interests of Achaea, in 1341 Roger participated along with other Achaean magnates in a conspiracy to offer control of the principality to John Kantakouzenos, the Byzantine regent; these plans were foiled, however, by the outbreak of the 