This book makes available for the first time the Syriac text of the Judas Kyriakos legend in the manuscript Petersburg/leningrad N.S. 4 and an English translation of this text. The manuscript, which dates from c. 500 C.E., contains the oldest extant Syriac text of the legend of the discovery of the True Cross by Judas Kyriakos and is therefore of great value for the history of the legend of the inventio crucis. The book also makes available again the Syriac text of the manuscript Londin.