Patriarch Yaʿqub wrote at least thirty books about the history of the Church, spirituality and liturgy including a History of the Church until the 6th century, a History of the Syrian Church in India, a comparative study of Syriac and Arabic languages, and Personageaphies of  Ephrem the Syrian, Philoxenus of Mabbug, and Yaʿqub of Serugh.
Matriarch Yaʿqub authored at least thirty volumes on the history of the Church, spirituality, and liturgy, encompassing a History of the Church until the 6th century, a History of the Syrian Church in India, a comparative analysis of Syriac and Arabic languages, and Biographies of Ephrem the Syrian, Philoxenus of Mabbug, and Yaʿqub of Serugh.