ACACIUS, patriarch of CONSTANTINOPOLIS. — From 471 to 489. When Basiliscus, the usurper of the imperial throne, imposed upon the bishops the subscription of an encyclical letter in which he condemned the doctrine of the Council of Chalcedon, A. refused, moved by the popular sentiment and by the monks of Constantinople, and in sign of mourning dressed the cathedra and the altar of Hagia Sophia in black. This earned him the appointment as legate by Pope Simplicius, and he took advantage of this office to depose many heretical bishops, protected also by the favour of the emperor Zeno, who had returned to the throne after having driven out the usurper Basiliscus (476).
Yet it was not disinterested zeal that animated A.: he aspired to achieve absolute independence from Rome and supremacy over all the Eastern Churches. It was probably from him, without any prior consultation with Rome, and certainly with his subscription, that the Henoticon was compiled, issued by Zeno (482): a formula of faith intended, as its name indicates, to unite all the subjects of the empire. In it was professed the faith sanctioned at Nicaea and Constantinople, but the faith of the Council of Chalcedon was tacitly repudiated.
Pope Felix III (II), through legates, ordered A. to render an account of his actions in Rome; when this order failed, he excommunicated and deposed him. The papal sentence, brought to Constantinople, was pinned by a bold monk to the pallium of A. while he was officiating in Hagia Sophia. In revenge, A. erased the name of Felix III from the diptychs and inaugurated that schism which is precisely named after him, the Acacian schism. It lasted from 484 to 519, when, on Easter Day, the patriarch John solemnly accepted the profession of faith proposed by Pope Hormisdas and struck A., Zeno and others from the sacred diptychs.