Why did the leaders of Europe want everyone in their empire or kingdom to convert to Christianity?

Question

What characteristics of Christianity did they like?

Answer 1

Simple answer because Christianity dictates its followers to convert as many as possible

Real answer: Control, as long as the subjects were christian it gave them the ability to control all aspects of their lives. Economic, social and spiritual.

Answer 2

During the Dark Ages, it was generally required that people follow the leader's religion. Some of it was to maintain a little bit of social control over people since there was little or no concept of a police department. Some of it was tradition handed down for generations among the various Celtic, Scandinavian, and Germanic tribes. So when a chieftan or king converted to Christianity, it was usually along with his subchiefs or "noble" class. The world then being a top-down society, the peasant class was expected to follow suit. This usually didn't sit well with the priestly class of the day since it robbed them of their power over the peasants (and nobility) and usually their wealth as well.

Answer 3

The turning point for this new religion in the Roman Empire was 313 C.E., the date of Emperor Constantine’s so-called conversion to “Christianity.” How did this conversion come about? In 306 C.E., Constantine succeeded his father and eventually, with Licinius, became coruler of the Roman Empire. He was influenced by his mother’s devotion to Christianity and his own belief in divine protection. Before he went to fight a battle near Rome at the Milvian Bridge in 312 C.E., he claimed that he was told in a dream to paint the “Christian” monogram—the Greek letters khi and rho, the first two letters of Christ’s name in Greek—on his soldiers’ shields. With this ‘sacred talisman,’ Constantine’s forces defeated his enemy Maxentius.
Shortly after winning the battle, Constantine claimed that he had become a believer, although he was not baptized until just prior to his death some 24 years later. He went on to obtain the support of the professed Christians in his empire by “his adoption of the [Greek letters] Chi-Rho [Artwork—Greek characters] as his emblem . . . The Chi-Rho had, however, already been used as a ligature [joining of letters] in both pagan and Christian contexts.”—The Crucible of Christianity, edited by Arnold Toynbee.
With Constantine’s support, Christendom’s religion became the official State religion of Rome. Elaine Pagels, a professor of religion, explains: “Christian bishops, once targets for arrest, torture, and execution, now received tax exemptions, gifts from the imperial treasury, prestige, and even influence at court; their churches gained new wealth, power, and prominence.” They had become friends of the emperor, friends of the Roman world.—James 4:4.

Under the topic “Church and State,” The Encyclopedia of Religion declares: “In the first three centuries AD the Christian church was largely isolated from official Roman society . . . Nevertheless, Christian leaders . . . taught obedience to Roman law and loyalty to the emperor, within the limits set by the Christian faith.”

In 1173, Henry II of England began using the title “King by the grace of God.” This led to the idea later known as the divine right of kings, meaning that the king’s power was hereditary. God supposedly manifested his choice in the fact of birth. In 1661, Louis XIV of France put an extreme version of this doctrine into operation by assuming total governmental control. He viewed opposition as a sin against the God he represented. “L’état c’est moi! I am the State!,” he boasted.

Answer 4

It was more of a power base thing than actually helping people out. It was their way of playing politics (and keeping the Muslims at bay).

The Christians, at that time, didn't know too much about Muslims and Jews because they didn't feel the need to get to know them better.

And that Jews killed Jesus? They were unaware that Jesus Himself is a Jew.

Answer 5

To have better control over the people. It kind of backfired, though, when the King and the Pope became at odds with each other.

Answer 6

The same reason they make you wear a uniform in Gym class.
Homogeneity.

Answer 7

They thought they were doing the right thing.

Humans can become mis-guided.

Peace!