Bishop Hovhannes is mentioned as the Primate of the Diocese of the Armenian Apostolic Orthodox Holy Church in Georgia in 1284.
In the same year, in 1284, during his governance, Archimandrite Hovhannes Erznkatsi, who was also known as Archimandrite Hovhannes Pluz, gave a sermon on the topic of the magnificence of God’s creations; cosmography and the motion of the heavenly creatures, in the Cathedral of Saint George (Surb Gevorg), which was built by a wealthy Armenian prince, Umek of Karin. The sermon-treatise of Archimandrite Hovhannes Pluz was highly praised and received great appreciation. (M. Chamchian “History of Armenia”, v. 3, Vienna 1786, p. 272).
Vachtang, the younger son of Prince Umek, who was an intelligent young boy, reputedly requested Archimandrite Hovhannes Erznkatsi to write down his sermon and bequeath it to him. Bishop Hovhannes also ordered Archimandrite Hovhannes Erznkatsi to write down his sermon and present it to him. Therefore, Hovhannes Erznkatsi wrote a book; “Understanding the wisdom, discourse about which starts in the heavens; about the motion of the heavenly creatures; about the orders in the year; about the seasons of the year and about other natural phenomena” (M. Chamchian “History of Armenia” v.3, Vienna, 1786, pp. 272-73).