Probably the most important achievement of Byzantium in its middle years was the Christianization of Russia and other parts of Eastern Europe. Among the most important consequences of the spread of Byzantine Christianity among Slavic and other peoples was the creation of a Byzantine commonwealth of independent kingdoms and cultures held together by a common faith. While influenced by Byzantine models, countries such as Russia developed their own art architecture and literature suitable to their language, customs and environment. Below are examples of medieval Russian literature. The first is a Russian edition of a treaty between the Pagan Russian and Christian Byzantines. Just as the Vikings had raided Western Christendom, free companies of Northmen (note the Scandinavian names in the document) and Slavs had made inroads into Byzantium using the riverine routes of above the Black Sea. To end this raiding, the Byzantine Empire initiated trading through this over favorable treaty.

A Byzantine-Russian Treaty of 911 A. D.
["Treaty with the Greeks (911)," in Anthology of Russian Literature From the Earliest Period to the Present Time, Leo Wiener, ed. and Tr. Pt. 1 (New York, 1902), pp. 41-44]

WE of the Russian nation, Karly, Inegeld, Farlof, Veremud, Rulav, Gudy, Ruald, Karn, Frelav, Ryuar, Aktevu, Truan, Lidulfost, Stemid, who were sent by Oleg, the Russian Grand Prince, and the illustrious boyars who are under his rule, to you, Leo and Alexander and Constantine, the Greek Emperors and great autocrats by the grace of God, to confirm and proclaim the amity which has existed for many years between the Christians and Russians, by the will of our princes and by the order of all those in Russia who are under his rule. Our illustrious Prince has often thought, more persistently than the others who have desired to maintain and proclaim the amity in God which has been between Christians and Russia, that not only with mere words, but also in writing and with a solemn oath made over our armour, ought such amity be proclaimed and confirmed, according to our faith and law. The following are the articles that we wish to establish in the faith of God and in love:

In the first place, we will make an agreement with you Greeks to love each other with our souls and as much as is in our power, and we will not permit, as far as is in our power, that harm or damage be done to any of you by those who are under the rule of our illustrious princes, but we will try, according to our ability, to preserve for ever and ever, unbroken and undisturbed, the amity which we profess both in words and in writing under oath. Likewise you Greeks shall preserve the same love to our illustrious Russian princes and to all who are under the rule of our illustrious Prince unpolluted and unchanged for ever and all time.

Under the head which is called damages we will agree as follows: Whatever may be made manifest in regard to a grievance, let the information of such grievance be accurate, and let not him be believed who begins the action; and let not that party take an oath if he deserve no belief; but if one swear according to his religion, let there be a punishment if perjury be found.

If a Russian kill a Christian, or a Christian a Russian, let him die where the murder has been committed. If he who has committed murder run away, then if he be possessed of property, let the nearest in kin to the murdered person receive that part which is his by law, and let the wife of the murderer have as much as belongs to her by law. If he who has committed the murder be destitute and have run away, let the case stand against him until he be found, and then he shall die.

If anyone strike another with a sword or beat him with a drinking vessel, let him for such striking or beating pay five litras of silver according to the Russian law. If the offender be destitute, let him pay as much as he can, and let him take off his upper garment which he wears, and besides let him swear according to his religion that there is no one to help him, and let the case against him forthwith be dropped.

If a Russian steal something from a Christian, or a Christian from a Russian, and the thief at the time when he commits the theft be caught by him who has lost the article, and the thief struggle and be killed, let not his death be avenged by either Christians or Russians, but let him who has lost take back what belongs to him. If a Russian despoil a Christian, or a Christian a Russian, by torture or by a show of force, or if he take anything away from a member of the druzhina, let him pay back threefold.

If a boat be cast by a great wind upon a strange shore, where there be any of our Russians, and someone come to furnish the boat with its belongings, we will take the boat through all dangerous places until it has smooth sailing. If such a boat cannot be returned to its place, on account of storm or impassable places, we Russians shall see the oarsmen off safe with their goods, if the accident happens near Greek land. But if the same happen near Russian land, we will take the boat to Russian territory, and let them sell the belongings of the boat and what else of the boat they can sell, and when we Russians shall go to Greece, with merchandise or with an embassy to your Emperor, the proceeds from the sale of the belongings of the boat shall be forwarded without hindrance. Should any man of the boat be killed, or beaten, by us Russians, or should anything be taken away, the wrongdoers shall be punished as above.

Should a Russian slave be stolen, or run away, or be sold by force, and a Russian make complaint of it, and the fact be ascertained in regard to the slave, then let him be returned to Russia. And if the merchants should lose a slave and make complaint thereof, let them search for him and let him be returned; should anyone prevent making such a search, then the local magistrate shall be responsible for him.

If a criminal should return to Greece from Russia, let Russia institute a complaint to the Christian Empire, and let the same be returned to Russia, even against his will.

All these things the Russians are to do to the Greeks, wherever such things may happen. To make the peace established between the Christians and Russians firm and lasting, we ordered this document to be written by John upon two charts and to be signed by the Emperor's and our own hand before the blessed cross and in the name of the holy Trinity and our one, true God, and to be proclaimed and to be delivered to our ambassadors. And we have sworn to your Emperor according to the law and custom of our nation, as being God's own creatures, not to depart, or let anyone else of our land depart, from the established treaty of peace and amity. This document we gave to your Empire in order to confirm the treaty on both sides and to confirm and proclaim the peace in your country, September the second, the fifteenth week, in the year from the creation of the world 6024 (911).