The medieval sequence was one of the most distinguished artistic achievements of the Carolingian age. In creating the genre, Frankish poet–musicians moulded text and music into a new and extraordinary synthesis, and created a composition that stood proudly apart from the Gregorian Propers that surrounded it in the Mass. The new style must have spread quickly throughout the Frankish Empire, eventually reaching well beyond its borders. Pieces from the earliest centres travelled far and wide and inspired new works at every turn — faithful imitations or adaptations, as well as works in which the style was consciously modified to reflect the different aesthetics of distant realms. The legacy of surviving sources, however, does not permit the details of these early developments to be traced; even the precise dates and places where the sequence was first cultivated remain obscure. The earliest surviving sources from most regions give access to only relatively mature stages of development, which already reveal a complex web of interrelationships that has been difficult to untangle.