E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Grim was a fisherman who rescued from a drifting boat an infant named Habloc, whom he adopted and brought up. This infant turned out to be the son of the king of Denmark, and when the boy was restored to his royal sire Grim was laden with gifts. He now returned to Lincolnshire and built the town which he called after his own name. The ancient seal of the town contains the names of Gryme and Habloc. This is the foundation of the mediæval tales about Havelock the Dane.