John bar Penkaye

John bar Penkaye ( "Yōḥannān bar Penkāyē") was a writer of the late seventh century who was a member of the Church of the East. He lived at the time of the fifth Umayyad caliph, Abd al-Malik ibn Marwan.
His surname indicates that his parents came from Feneq, on the Tigris east of Tur Abdin. He was a monk at the monastery of Mar John of Kamul, and later at the monastery of Mar Bassima. Later writers confuse him with John Saba of Dalyatha.
John bar Penkaye's writings provides an eyewitness account of the early Muslim conquests of his time. 
Works.
A number of his works are still in existence. Most of them have never been published and are extant only in manuscripts.
"Ktâbâ d-rêš mellê" or "Summary history of the world".
This is in 15 books.