he was literally a child of the Rhine, his father being a water-monster

In the middle of the fifth century arose the powerful dynasty of the Merovingians, one of the most picturesque royal houses in the roll of history. In their records we see the clash of barbarism with advancement, the bizarre tints of a semi-civilization unequalled in rude magnificence. Giant shadows of forgotten kings stalk across the canvas, their royal purple intermingling with the shaggy fell of the bear and wolf. One, Chilperic, a subtle grammarian and the inventor of new alphabetic symbols, is yet the most implacable of his race, the murderer of his wife, the heartless slayer of hundreds, to whom human life is as that of cattle skilled in the administration of poison, a picturesque cut-throat. Others are weaklings, fainéants; but one, the most dread woman in Frankish history, Fredegonda, the queen of Chilperic, towers above all in this masque of slaughter and treachery.

Tradition makes claim that Andernach was the cradle of the Merovingian dynasty. In proof of this are shown the extensive ruins of the palace of these ancient Frankish kings. Merovig, from whom the race derived its name, was said to be the son of Clodio, but legend relates far otherwise. In name and origin he was literally a child of the Rhine, his father being a water-monster who seized the wife of Clodio while bathing in that river. In time she gave birth to a child, more monster than man, the spine being covered with bristles, fingers and toes webbed, eyes covered with a film, and thighs and legs horny with large shining scales. Clodio, though aware of the real paternity of this creature, adopted it as his own son, as did King Minos in the case of the Minotaur, giving him the name Merovig from his piscatory origin. On Clodio’s death the demi-monster succeeded to the throne, and from him sprang a long line of sovereigns, worthless and imbecile for the most part.

Childeric, the son and successor of Merovig, enraged his people to such a degree by his excesses that they drove him from throne and country. One friend alone remained to him, Winomadus, who, having no female relations to suffer by the king’s attentions, did not find the friendship so irksome as others; indeed, had been a partner in his licentious pleasures. He undertook to watch over the interests of Childeric during his enforced absence in Thuringia at the court of Basinus, king of that country. The Franks had elected Aegidius, a Roman general, to the sovereignty over them, but as he proved himself no better than Childeric, whom they had deposed, they once more essayed to choose another ruler. This was made known to Childeric through his friend Winomadus. He rapidly returned to the shores of the Rhine and, reinforcing his following as he proceeded on his march, appeared before Andernach at the head of a formidable force, composed of many of his former subjects, together with Thuringian auxiliaries. The people of Andernach, unable to resist this overwhelming argument, again accepted Childeric as their king.

(Lewis Spence, Hero Tales and Legends of the Rhine, London; New York: 1915)