 An inscription on the colophon says, in Hebrew, that "Obadiah the Norman proselyte" who converted to Judaism "in the month of Elul" of 1102 has written the prayer-book "with his own hand".So, although in all of his writings he invariably refers to himself in the third person, by directly comparing the handwriting we can be sure that it is indeed he who wrote it.It took scholars over half a century to build a full picture of Obadiah's life and deeds.