Sinai Syriac 16 has been of the greatest importance in the recovery of a document from early Church history. Eusebius records that Aristides of Athens was the first to make a defence of Christianity before a Roman emperor, and he gives an extract from an apology presented by a certain Quadratus, ‘a mere brick from a vanished house.’ In 1889, J. Rendel Harris was able to spend some weeks at Sinai, reading the Syriac manuscripts. He was astonished to see that Sinai Syriac 16 contains the Apology of Aristides, which until then had been thought lost. He writes, ‘We were so happy as to discover this text in a volume of St Catharine, upon Mount Sinai, during a delightful visit which we paid to those majestic solitudes and silences in the spring of 1889.’ But the words were somehow familiar. As it turns out, Saint John of Damascus, who lived in the eighth century, had incorporated the Apology of Aristides into his tale of Barlaam and Ioasaph. Thus the text of the Apology itself had been preserved, but it was only this manuscript that allowed such an identification, and the recovery of an important moment in the history of the early Church.