Childeric.
“THE laws of matrimony, amongst the Germans, says Tacitus, are strictly observed. Vice is not there a subject of ridicule. To corrupt or be corrupted is not called fashion, or the custom of the age. There are few examples, in this populous nation, of the violation of conjugal faith.”
This was the reason of the expulsion of Childeric: he shocked their rigid virtue, which conquest had not had time to corrupt.