The Byzantine Empire is a term used by modern historians to distinguish the Constantinople-centered Roman Empire of the Medieval period from its earlier classic incarnation. The process by which the empire waned, and from when to mark its decline is matter of scholarly debate. Enlightenment writers such as Edward Gibbon, their view colored by pro-western, and anti-clerical biases tended to see the whole ten century history empire as a sad codicil to the Roman Empire of Antiquity. Late-20th-century and 21st-century historians have instead emphasized the empire's remarkable resiliency and adaptability to change.