Constantinian

Constantinian refers to anything associated with Constantine the Great (c. 272–337) or the Constantinian dynasty that governed parts of the Roman Empire in the 4th century. The term is used in history, theology, and art history to denote policies, institutions, or cultural forms characteristic of that era.

Constantine I, who reigned from 306 to 337, established Byzantium as a major capital and formally renamed it Constantinople in 330. He pursued reforms aimed at stabilizing the empire and reorganizing administration. He endorsed the legalization of Christianity with the Edict of Milan in 313, promoted the Christian Church, and supported the First Council of Nicaea in 325, which produced the Nicene Creed and set a precedent for doctrinal unity.

The Constantinian dynasty refers to Constantine's lineage and his male successors who briefly shared power in the late 4th century, consolidating imperial authority and Christian endorsement within the empire. In broader scholarship, the term is used to describe the transformation commonly called the Constantinian shift, the process by which Christianity moved from tolerated status to a favored, integrated component of imperial policy and governance.

The term appears across disciplines such as history, religious studies, art history, and archaeology when referencing era-specific policies, monuments, or religious developments.