Much like the sword-wielding Norseman depicted on its front sleeve, the eponymous debut album from Ensiferum unexpectedly invaded the new millennium's budding Viking metal landscape, speedily conquered the loyalties of unsuspecting listeners, and proceeded to set up a permanent settlement within the hearts of many devoted metal fans of all stripes.

The strategy for this wholesale takeover was really quite simple, as the Finnish band obviously took stock of the broad inspirational foundations laid down by Sweden's pioneering Bathory before matching them with the more readily accessible songcraft perfected by countrymen Amorphis (while wisely subtracting Finntroll's goofy polka rhythms), to achieve a finely balanced and damn near irresistible Viking folk-metal formula.

Move ahead three years and the group apparently developed an ambition to follow Metallica's trail towards world domination, as well, and enlisted the services of their former associate, Flemming Rasmussen, to engineer and mix their sophomore outing -- sparingly but emphatically named Iron -- at the same Sweet Silence studios in Copenhagen that spawned Ride the Lightning and Master of Puppets.

It's therefore no surprise that the album's captivating opening instrumental, "Ferrum Aeternum," sounds rather like a folk-metal interpretation of Ennio Morricone's Spaghetti Western classic, "The Ecstasy of Gold" (which of course remains Metallica's concert-opening theme); nor that ensuing numbers like "Sword Chant," "Into Battle," and the title cut bask in the kinetic rush of old-school thrash for inspiration.

Conversely, songs like "Tale of Revenge" and "Slayer of Light" bear a more pronounced keyboard presence thanks to newly instated bandmember Meiju Enho, while the majestic march of "Lost in Despair" and the amusingly named "Lai Lai Hei" boast enough compositional flexibility for singer Jari Mäenpää to attempt some surprisingly operatic vocals.

Ultimately, Iron is distinguished by further sonic extremes than its predecessor, and despite lacking some of that album's songwriting and stylistic consistency, it once again succeeded in hammering all of those often challenging Viking metal hallmarks into uncommonly immediate song templates.

Ok, so achieving universal success on par with Metallica's may have proved too tall an order, in the end, but Iron nevertheless converted numerous new extreme metal fans to Ensiferum's cause.