From New World Encyclopedia
Unification Aspects:

The Divine Principle recognizes the providential purpose of four great civilizations, one of which is the Islamic. For a long period of history, the Mamluks as rulers of Egypt enabled the survival of the Abbasid caliphs, as a symbol of Muslim unity.

The Mamluks themselves rose from slave-soldiers to become sultans. Their contribution to providential history can be identified as enabling the survival of a trans-national system of faith and practice, the religion of Islam. This gave millions of people a set of shared values and a religious worldview.
Unification Aspects is designed to relate the subject of this article to Unification Thought and to aid
teachers and researchers who wish to further pursue these topics from a unification perspective.