The Avalon Project lists several primary source documents that relevant to medieval history.

Epistolae is a collection of medieval Latin letters to and from women. The letters collected date from the 4th to the 13th centuries, and they are presented in their original Latin as well as in English translation. The letters are organized by the name and biography of the women writers or recipients. Biographical sketches of the women, descriptions of the subject matter of the letters, and the historical context of the correspondence are included where available.

Manuscripts Online enables you to search a diverse body of online primary resources relating to written and early printed culture in Britain during the period 1000 to 1500. The resources include literary manuscripts, historical documents and early printed books which are located on websites owned by libraries, archives, universities and publishers.

The world's largest searchable database of Middle English lexicon and usage for the period 1100-1500.