Bibliographical Note:--Nearly all the important sources for a study of this subject are in Latin. Among them are, Mansi, _Sacrorum Conciliorum_; Jaffé, _Regesta Pontificum_; _Corpus Juris Canonici_; _Corpus Juris Civilis_; Pertz, _Monumenta Historica Germania_; Niebuhr, _Corpus Byzantinæ_; Migne, _Patrologia_; Potthast, _Bibliotheca Historica Medii Ævi_. B.--SECONDARY: I.--SPECIAL: 1.--Allies, T. W., _Church and State as Seen in the Formation of Christendom_. Lond., 1882. 2.--Armitage, W., _Sketches of the Church and State in the First Eight Centuries_. Lond., 1888. 3.--Bryce, _The Holy Roman Empire_. Var. eds. 4.--Bury, J. B., _The Later Roman Empire_. Edinb., 1889. 2 vols. 5.--Carr, A., _The Church and the Roman Empire_. Lond., 1887. 6.--Church, R. W., _Relations between Church and State_. Lond., 1881. _Beginnings of the Middle Ages._ Lond., 1895. 7.--Croke, A. D., _History of the Church under the Roman Empire_ (to 476). Lond., 1873. 8.--Cutts, E. L., _Charlemagne and His Times_. Lond., 1878. _Union of Church and State._ Lond., 1881. 9.--Emerton, E., _Introduction to the Middle Ages_. Bost., 1888. _Mediæval Europe._ Bost., 1894. 10.--Fisher, H. A. L., _The Mediæval Empire_. 11.--Geffcken, H., _Church and State_. Lond., 1877. 2 vols. 12.--Gibbon, E., _Decline and Fall of the Roman Empire_. Var. eds. 13.--Gierke, O., _Political Theories of the Middle Ages_. Lond., 1900. 14.--Greenwood, A. D., _Empire and Papacy in the Middle Ages_. Lond., 1896. 15.--Greenwood, T., _Cathedra Petri_. Lond., 1859-72. 5 vols. 16.--Gregorovius, F. A., _Rome in the Middle Ages_. Lond., 1900. 17.--Gosselin, J. E. A., _Power of the Pope During the Middle Ages_. Lond., 1853. 18.--Hardy, E. G., _Christianity and the Roman Government_. Lond., 1893. 19.--Hodgkin, T., _Italy and Her Invaders_. Oxf., 1892-9. _Charles the Great._ Lond., 1896. _Theodosius._ Oxf., 1889. _Theodoric._ N. Y., 1891. 20.--Hussey, R., _Rise of the Papal Power_. Lond., 1863. 21.--Hergenröther, J. A. G., _The Catholic Church and the Christian State_. Lond., 1876. 2 vols. 22.--James, G. P. R., _History of Charlemagne_. Lond., 1832. 23.--Lea, H. C., _Studies in Church History_. Phil., 1869. 24.--Mann, H. K., _The Lives of the Popes in the Early Middle Ages_. Lond., 1905. 25.--Manning, H. E., _The Temporal Power of the Vicar of Jesus Christ_. Lond., 1862. 26.--Mombert, J. I., _History of Charles the Great_. N. Y., 1888. 27.--Oman, C. W. C., _The Dark Ages_ (476-918). Lond., 1893. 28.--Pressensé, E. de, _History of Church and State_. Lond., 1869.