Parts of this book are based on materials originally published by Vassilka Tapkova-Zaimova and Anissava Miltenova some fifteen years ago in Bulgarian ("Историко-апокалиптичната книжнина във Византия и в средновековна България", Sofia, 1996), which have been wholly revised, expanded and translated into English for the present edition. Five new chapters have been also included on the papers previously published in various Bulgarian journals and anthologies and therefore until now inaccessible to many potential readers.