Which Ecumenical Council is often considered the last of the classical councils?

The Second Vatican Council is often mistakenly thought of as the last of the classical councils due to its significant impact on the Catholic Church and its modern ecclesiology. However, in the context of traditional ecumenical councils that address doctrinal issues and establish foundational church teachings, the Council of Chalcedon is recognized as the last of the classical councils. This council, held in 451 AD, defined the two natures of Christ and reinforced the authority of the bishops of Rome, setting the stage for subsequent theological development.

The Second Vatican Council, held in the 20th century, focused on liturgical reform, ecumenism, and the Church's relationship with the modern world, representing a shift in focus rather than a continuation of the doctrinal debates characteristic of the earlier councils. Therefore, while the Second Vatican Council is of great importance in the contemporary Church, it does not fit the definition of a classical ecumenical council in the same way as Chalcedon.