What main heresy was condemned at the Council of Constantinople II?

The main heresy condemned at the Council of Constantinople II, which took place in 553, was Monophysitism. This council addressed the Christological controversies that had arisen regarding the nature of Christ. Monophysitism, which posited that Christ has only one nature—a divine one—denies the reality of the two natures of Christ, as affirmed by the earlier Councils of Nicaea and Chalcedon. The rejection of this heresy was crucial in reaffirming the orthodox Christian belief in the dual nature of Christ, one fully divine and one fully human, existing in one person.

By condemning Monophysitism, the Council worked towards restoring unity within the church and clarifying the theological understanding of Christ's nature. The outcome was significant in solidifying the Christological framework that upheld the belief in both the humanity and divinity of Jesus, which has been foundational for mainstream Christian theology.