In the Middle Ages, efforts were made in order to establish a single Christian state of Pan-Christianity by uniting the countries within Christendom.[1][2]Christian nationalism may have played a role in this era in which Christians felt the impulse to recover lands in which Christianity flourished.[3] After the rise of Islam, certain parts of North Africa, East Asia, Southern Europe, Central Asia, and the Middle East lost Christian control.[4] In response, Christians across national borders mobilized militarily and a "wave of Christian reconquest achieved the recovery of Spain, Portugal, and southern Italy, but was unable to recover North Africa nor—from a Christian point of view, most painful of all—the Holy Land of Christendom."[4]
^Snyder, Louis L. (1990). Encyclopedia of Nationalism. St. James Press. p. 282. ISBN978-1-55862-101-5. Major religions in the past, especially Christianity, have attempted to include all their adherents in a large union, but they have not been successful. Throughout most of the Middle Ages in Western Europe, attempts were made again and again to unite all the Christian world into a kind of Pan-Christianity, which would combine all Christians in a secular-religious state as a successor to the Roman Empire.
^Snyder, Louis Leo (1984). Macro-nationalisms: A History of the Pan-movements. Greenwood Press. p. 129. ISBN978-0-313-23191-9. Throughout the better part of the Middle Ages, elaborate attempts were made to create what was, in effect, a Pan-Christianity, an effort to unite "all" the Western Christian world into a successor state of the Roman Empire.
^Parole de l'Orient, Volume 30. Université Saint-Esprit. 2005. p. 488.
^ abLewis, Bernard Ellis; Churchill, Buntzie Ellis (2008). Islam: The Religion and the People. Pearson Prentice Hall. p. 76. ISBN978-0-13-271606-2.