At the beginning of his reign, Vladimir showed an unusual devotion to the old Slav gods. He erected idols on the sandy cliffs of Kief; that of Perun had a head of silver and a beard of gold. It seems that after some time he became displeased with this religion and, Nestor tells us, he grew anxious to know what religion was the best. He, therefore, sent deputies to Bulgaria to study the Moslem or Mohammedan creed, and to the Khazars, who occupied the plain between the Bug and the Volga, to make inquiries about the Jewish faith. From the Poles and Germans he wanted to know all about the Roman Catholic Church, and at Constantinople he expected to learn of the Greek faith. When these deputies returned and reported to him, Vladimir selected the Greek Church, which choice was approved by his drujina; if the Greek religion had not been the best, your grandmother Olga, the wisest of mortals, would not have adopted it," said they. Thus Vladimir became a convert; but his method of showing it was rather peculiar.

He might have been baptized by the bishop of Kief; or, if he had applied at Constantinople, the emperor would gladly have sent him a high prelate to perform the service. Instead of this, Vladimir collected an army and marched against Kherson,—the last city in Russia held by the Byzantine. It was taken by means of treachery, and from this city Vladimir sent to Constantinople to demand in marriage the sister of the two emperors Basil and Constantine. Although the emperors did not like the proposed connection, they consented because they feared an invasion, but made it a condition that Vladimir should be baptized. The ceremony was performed at Kherson; soon after the bride arrived and the marriage took place in the same city. When he returned to Kief, he carried with him the priests and sacred ornaments taken from the churches of Kherson.

Upon his return to Kief, he began missionary work by his own peculiar methods. His first orders were to pull down the idols; during the execution the people wept, moaned, and wrung their hands. Perun's image was handsomely flogged and thrown into the Dnieper. Since it was made of wood, it soon came to the surface, which was looked upon as a miracle by the people who rushed down to worship it. But Vladimir's soldiers gave it another bath, and this time it was caught by the current and drifted away. The cliff where it stood is still known at Fief as "the devil's leap," and the spot where Perun floated ashore, is shown to visitors.

After thus getting rid of the idols, Vladimir commanded the people of Kief, men, women, and children, to plunge into the Dnieper, which had been consecrated for the occasion, that they might be baptized. When they had obeyed his order, the priests read the service, so that after entering into the river as heathen, they left it as Christians. The people of Novgorod were converted in the same swift and practical manner, since no attention was paid to their objections.

Heathen temples were next converted into churches, which were decorated by Greek artists. Vladimir erected at Kief the church of St. Basil, on the place where Perun's image had stood. Numerous other churches were built; he also founded schools where the Bible was taught in the Slav language. At first the people objected to send their children, because they looked upon reading and writing as magic. But Vladimir had persuasive ways, and was not likely to be deterred by such opposition. Nestor admired him very much. He says that Vladimir was a different man after he had been converted; that he was so afraid of committing a sin, that he hesitated to inflict capital punishment, until the bishop reminded him that crime must be punished. He also divided his income among the churches, and thus became the Saint Vladimir of Russia. Popular ballads keep alive the memory of the first Christian prince. He is often mentioned in them as "The Beautiful Sun" of Kief.

It cannot be supposed that the Russian people were converted at once into good Christians by Vladimir's forceful method. Several centuries were to pass away before the peasants could be induced to part with their heathen customs. The priests preferred to let them remain under a Christian name. There is something mystic in the Slav character. He nurses the belief in magicians and sorcerers, which has never been uprooted. It is seen at present in the worship of the eikon  or saint's image.

Vladimir died in 1015. He, too, divided Russia among his numerous sons. One of them, Iaroslaf, received Novgorod, where he began to interfere with the rights of the people. A deputation of leading citizens came to him with a protest. He ordered their arrest and condemned them to death. Meanwhile Vladimir's other heirs had indulged in the usual quarrels and wars, until it seemed as if Sviatopolk, a nephew, would become the sole ruler. Iaroslaf then called the principal people of Novgorod together, and threw himself upon their generosity. They forgave him and promised their support. They kept their word, and after a long and bloody war he entered Kief as his father's successor.

Iaroslaf was unfortunate in a war with the Byzantine Empire. The Russian fleet was badly defeated in the Bosphorus: 8,000 men were killed, and 800 prisoners were taken to Constantinople.

Of greater importance was Iaroslaf's work at home. He built churches and monasteries; St. Sophia church was the pride of Kief; the monastery of The Catacombs still draws pilgrims from all parts of Russia. Kief became known as "the city of four hundred churches." He also founded a school for three hundred boys at Novgorod, thereby showing that Russia at that time was second to no European nation.

Kief, under his reign, was one of the most prosperous cities. This was due to her situation on the Dnieper and her trade with the Byzantine Empire, to the great fertility of the Black Earth land, and to Iaroslaf's connection by marriage with the reigning families of Europe. Of his daughters Elizabeth was the wife of the King of Norway, Anne of the King of France, and Anastasia of the King of Hungary; his sister Mary was married to the King of Poland, and his sons had married into royal families. Merchants from Holland, Germany, Hungary, and Scandinavia were established at Kief. The Dnieper was alive with merchant vessels, and she counted eight markets. It is evident that Iaroslaf took pains to protect and advance commerce. He had coins minted with his Slav name on one side, and his Christian name Ioury (George), on the other.

Perhaps his greatest work is the code of laws established by him, known as the Russkaļa Pravda  or Russian Right. Though necessarily primitive, it was a long step in advance of that time. It followed chiefly the ideas of right and wrong according to the conceptions of the Scandinavians.

At this time, although the dignity of kniaz, duke or prince, was hereditary in the family of Rurik, it was understood by all parties that the reign of the prince depended upon the consent of his subjects, and perhaps more still upon that of his drujina. A story is told that in Vladimir's time the drujina complained that they were made to eat from wooden bowls, whereupon he gave them silver ones, saying: I could not buy myself a drujina with gold and silver; but with a drujina, I can acquire gold and silver, as did my father and my grandfather.

Ever since Kief had been the residence of Rurik's descendants, they had been recognized as Grand Dukes, because they represented the eldest of the descendants. They did not, as a rule, interfere with the administration, but were the dukes, the commanders of the armies. Many districts had such a duke, who was, however, invariably of the blood of Rurik, and recognized the superior authority as the eldest of the blood. When the Grand Duke of Kief died, he was not succeeded by his son, unless he had neither uncle nor brother living; but it was within the power of the grand duke to leave one or more districts to his sons.

The descendants of the Norsemen were, therefore, the defenders of the districts which they ruled as dukes. Novgorod and Pskof were republics on the northwest frontier, and usually had the same duke. Smolensk was an important dukedom, because it contained the sources of the Volga, the Dnieper, and the Dwina, and embraced the ancient forest of Okof. Not far from it was the dukedom of Toropetz. On the Upper Oka was Tchernigof—a rival of Kief; further to the south was Novgorod-Swerki, and east of the Upper Don, extending as far as the Oka, were Riazan and Mourom. The dukedom of Souzdal, inhabited by a mixture of Finns and Slavs, was in the north, the soil still covered by forests. Southeast Russia embraced Red Russia, that is Volhynia and Gallicia Proper.

The introduction of the Greek Church caused important changes. The Greek Priests could not comprehend the relation between the people and its defenders. To them the duke was not a dux  (leader), but a Cęsar, Kaiser, or Czar, ruling, not with the consent of the governed, but by the grace of God, as did the emperors at Constantinople. This idea gradually penetrated into the minds of the several dukes, until it was accepted and enforced by them.

Another very important change was effected by the Greek religion. We have seen that according to the old Slav customs, it was not the son who succeeded as the head of the family, but its eldest member. It appears that the same custom prevailed among the Norsemen, as we have seen that it was Rurik's brother, and not his son who succeeded him. In the Byzantine Empire, the oldest son was the heir, and the priests tried to introduce this as a law.

As the descendants of Rurik increased in number, it was not always easy to determine who was entitled to the succession. Hence there were often several claimants, and as a result, civil wars followed. These wars, strange as it may appear, served to bind the dukedoms together, because most of them were waged for the purpose of establishing the claim of a duke upon the possession of Kief.

Iaroslaf died in 1054, and was buried in the church of St. Sophia at Kief. In his will we see the effect of the Greek Church, for he specially appointed his eldest son Isiaslaf as his successor. A younger brother, Sviatoslaf, took up arms, and expelled him in 1073. Upon his death in 1076, Isiaslaf returned to Kief, where he lived two years. He died in 1078, and was succeeded by his brother Vsevolod, who was grand duke until 1093, when he was succeeded by Sviatopolk, the son of Isiaslaf, as the eldest of the family. He was not opposed by Vsevolod's famous son Vladimir Monomachus, who admitted that Sviatopolk's "father was older than mine, and reigned first in Kief."