When the people of Sevrin speak of narwhals, they might be talking about the small, tusked whales that summer in the shallow waters around Sevrin's northern islands. More likely they're referring to Narwhal Harbor, a legendary seaport on Stormwall island, and the pirates who once ruled it.
Like many island cultures, Sevrin has a history of piracy. It is particularly suited to raiding parties of several small ships--the famed Narwhal "pods"--which could disappear into rocky coves impassible to larger ships. But large-scale piracy was also practiced, with some pirate lords commanding fleets of well armed vessels.
When Eldreath rose to power, he seized control of Stormwall Island, Sevrin's only deep-water port. He razed Narwhal Harbor, the dock city, in a stunning and brutal display of magic that also burned every pirate ship in the harbor down to the waterline. He placed Timmony Blackheart, the most powerful and brutal of the pirate lords, in charge of the ancient stone keep (most recently known as Muldonny Manor) and paid him handsomely to hunt down his former comrades and competitors.
This action won Eldreath considerable approval and support from rulers of other lands, many of whom sent ships and fighters to help this law-abiding lord consolidate his rule over the pirate islands. Any foreigners who might have harbored a secondary agenda and ambitions of their own soon learned that Eldreath was not inclined to share power or territory.
Some coastal raiding continued, however, and even after several generations of Eldreath's reign, the Narwhal tradition ran deep. The adepts' rise to power was in no small part due to a fleet of raiders, fishermen, and merchant seamen who formed a blockade around the island to ward off any who might come to the sorcerer's aid. Once the battle was won, the adepts wisely put the raiders to work as sanctioned bounty hunters, thus giving rise to the Gatherers.