Middle Ages
Christianity/Christian Thinkers
A Bible (Douay-Rheims & ?Clementina Vulgata or KJV or, if you really feeling punctilious you could choose an Hebrew-Greek-English interlinear, which is hard to find a reliable/accurate version of)
Anselm of Canterbury: Major Works (Oxford)
Summa Theologica by St. Aquinas
Confessions by St. Augustine (Oxford)
City of God by St. Augustine
On Christian Teaching by St. Augustine
Eusebius: The Church History
Middle Eastern Thinkers
The Guide for the Perplexed by Maimonides
Ethical Writings of Maimonides
Averros: His Life, Work, and Influence
Averros: The Incoherence of the Incoherence (response to the work below)
The Incoherence of the Philosophers by al-Ghazali
Avicenna by Lenn E. Goodman
The Metaphysics of the Healing by Avicenna
Medieval Philosophy
Philo of Alexandria
Duns Scotus: Philosophical Writings: A Selection
On Signs by Roger Bacon
Ockham: Philosophical Writings: A Selection
The British Isles
The History of the English People: 1000-1154 (Oxford)
Early Irish Myths and Sagas (Penguin)
The Book of Margery Kempe (Oxford)
The Chronicle of the Abbey of Bury St. Edmonds (Oxford)
The History of the Kings of Britain
The Journey through Wales and Description of Wales (Penguin)
The History and Topography of Ireland
Arthurian Romances
The Anglo-Saxon World: An Anthology (Oxford)
Beowulf
Le Morte D'Arthur (Oxford)
Mabinogion (Oxford)
Sir Gawain & the Green Knight
The Ecclesiastical History of the English People… by Bede (Oxford)
Germany
Oera Linda Book
Tristan w/ Tristan of Thomas (Penguin)
The Nibelungenlied (Penguin)
Parzival (Penguin)
Scandinavia + Iceland
King Harald's Saga (Penguin)
Vinland Sagas (Penguin)
Egil's Saga (Penguin)
Saga of the Volsungs
Prose Edda
Poetic Edda
The Kalevala
Laxdaela Saga (Penguin)
Grettir's Saga (Oxford)
Erik the Red and Other Icelandic Sagas (Oxford)
Russia
Medieval Russia's Epics, Chronicles, and Tales (Oxford)
Spain
St. John of the Cross: "Complete Works"
The Poem of the Cid
France
Two Lives of Charlemagne (Penguin)
A History of the Franks
The Song of Roland
Abelard and Heloise: Letters & Other Writings
Byzantine/Greek
Fourteen Byzantine Rulers (Penguin)
Alexiad (Penguin)
Digenis Akritas: Two-Blood Border Lord
There is a work in Byzantine Greek which I can't recall
The Digest of Roman Law by Justinian (Penguin)
The Secret History of Procopius
Chronicles of the Crusades (Penguin) Note: I'm placing this in the Byzantine category as its geographically related and contains two accounts of the Crusades
Italy
Travels of Marco Polo
The Complete Canzoniere by Petrarch
Divine Comedy by Dante
The Decameron by Boccaccio (Oxford)
