King Clovis and Christianity
King Clovis not only greatly expanded the Frankish empire, but also spread Christianity.
Clovis' conversion story is intertwined with legends. For example, at the lowest point of a battle against the Alamanni, Clovis is said to have invoked the Germanic god of war Wodan, but without effect. So he invoked the god of his Christian wife, promising to repent if he won the battle. In the end, he almost miraculously won. Clovis kept his promise and was baptized. The story goes that his two sisters and 3000 of his warriors followed him.
This is a beautiful story, which Clovis deliberately used as a means of propaganda. Its truth can be strongly questioned. The conversion appears to have been primarily a strategic political move by Clovis. It made him the hero of the Christian population.