Hiereia
Hiereia ( Greek Ίερεία ; today Kadıköy , Istanbul district ) was a suburb of Constantinople on the Asian side of the Bosporus . The city was east of Chalcedony on a small peninsula on the coast of the Marmara Sea . Emperor Justinian I built a palace with a harbor and a church dedicated to St. Mary here . Emperor Herakleios also resided in Hiereia, as did Basil I , who had a chapel built for the prophet Elijah . Due to its status as an imperial summer residence, Hiereia was often the site of triumphal procession after successful wars in the east.
In 754, Emperor Constantine V called a council to Hiereia , which condemned the worship of icons (see Byzantine Iconoclasm ) and posthumously declared the church father John of Damascus († 749 ) a heretic . It was declared invalid at the Second Council of Nicaea .
Coordinates: 40 ° 58 ' N , 29 ° 3' E