The Catholic Encyclopedia
A useful tool for individuals studying topics related to Medieval religion and society, the Catholic Encyclopedia provides information on the interests, actions, and doctrines of the Catholic Church.
Christian History Handbook
This useful site addresses the history of Christianity from the ancient world of Rome to the mid-16th century. Users can choose between Ancient, Medieval and Early Modern sections, with each section then divided into topics. Each section also provides users with bibliographies, syllabi, and study guides.
Christianity (The Warburg Institute)
This site provides excellent links to information and texts related to Christianity. Included are links to the Catholic encyclopedia, histories of the Church, various editions of the Bible, an index of saints, and descriptions and texts of the Church Fathers, mendicant orders, and mystics.
Christian Classics Ethereal Library
This site provides free access to English versions of hundreds of classic Christian writings, including the texts of the Church Fathers and the Bible. The site also includes an archive of hymns.
On online resource for information on the Church of the Middle Ages, this site covers church history from the rise of the Papacy to the time of the Reformation. Though the events, individuals, institutions, and doctrines listed are only provided with brief descriptions, each entry is presented with a useful list of relevant sources (e.g. primary and secondary sources, online links, etc.).