John XIII Aaron bar Ma'dani was the Patriarch of Antioch, and head of the Syriac Orthodox Church from 1252 until his death in 1263.
In 1230, Aaron was ordained as metropolitan of Mardin, upon which he assumed the name John and two years later he was elevated to maphrian by Ignatius III David.
John was patriarch for eleven years before his death in 1263 at the Baqismat Monastery in Sis, Cilician Armenia.
As well as this John wrote an ode to Aaron the Ascetic and a forty-seven page anthology, containing his most famous poem, The Bird.
In addition to this, John wrote a liturgy and seven canons, six of which he issued at the Monastery of Mor Hananyo and the seventh was included in his early patriarchal proclamations.