On the plateau (Konstantinshöhe) near the airport (in the direction of Hotel Konstantin). At this point, in 312, Emperor Constantine had the vision In this sign you will conquer. (but is not the only place where this is claimed)
> After Diocletian's abdication (305 AD) there was hopeless confusion, because the succession could not be arranged as he had planned. This system, it turned out, only had a chance of surviving with a strong personality like his. In the struggle of the various candidates for the succession, Constantine (Flavius Valerius Constantinus) was able to prevail over Maxentius, the son of Maximian, in a battle at the Milvian Bridge in Rome in 312 and thus became the sole ruler in the western part of the empire.
According to legend, on the night before the decisive battle, Constantine saw a flaming cross with the inscription: In hoc signo vinces = In this sign you will win. The emperor then had his soldiers awakened and placed the sign of the cross on their shields. When Constantine was then able to win a brilliant victory, he was convinced of the blessing power of God for Christians and tolerated Christianity (313 Edict of Milan). Constantine himself was baptized only on his deathbed. In 391 Theodosius made Christianity the state religion.