 The date of his birth is likewise unknown , but as he is called an " old man " in 1258 , it must have been around the turn of the 13th century . Of his own family , it is known that he had one son , Constantine , who according to George Pachymeres was married to a daughter of the sebastokrator Isaac Doukas Vatatzes , brother of the Nicaean emperor John III Doukas Vatatzes . 
