The Avalon Project contains transcribed sources "relevant to the fields of Law, History, Economics, Politics, Diplomacy and Government" from all historical periods, including numerous medieval sources.
"Thousands of digital images from the Library’s renowned collection of medieval and Renaissance manuscripts are now available in CORSAIR. The collection spans some ten centuries of Western illumination, and contains manuscripts from all the major schools, including some of the great masterpieces of medieval manuscript art."
"De Re Militari, begun in 1992, is the Society for the Study of Medieval Military History. Here we host many primary sources, articles, dissertations, and resources for the study of military actions, technology, and topics from the fall of Rome to early seventeenth century. We also have an active online Book Reviews section.We are the principle online source for scholarly information about warfare in the Middle Ages."
"Epistolae is a collection of letters to and from women dating from the 4th to the 13th century AD. These letters from the Middle Ages, written in Latin, are presented with English translations and are organized by the women participating. Biographical sketches of the women and descriptions of the subject matter or the historic context of the letter is included where available."