A lot of people will tell you that Viking metal is not a 'genre'. You'll hear them say "technically, [moist inhalation] it's a lyrical theme". That's true! I can't argue that. But defining a style of music is just as legitimate by lyrical theme as it is any other way, such as the way you hold your drumstick or how you move your hand when playing guitar. To say that a lyrical theme can't define a genre suggests that vocalists and songwriters are somehow less important than instrument players, which is quite frankly horseshit, especially when you consider that the lyrical content is usually something agreed upon by the entire band BECAUSE IT DEFINES THEM. So haters, I speak unto thee the official Also, Wolves pejorative: suck flaming balls.
There they are. Go suck 'em.
Honestly, it's just because I'm lazy. It's easier to say 'Viking metal' than 'black metal with a Viking-related lyrical theme'. If you have an issue with that, see above re: balls, flaming, to be sucked (by you).
Also I got $20 that says if I referred to Amon Amarth as death (or even better melo/death) some coprophage is going to be all like "wtf Amon Amarth is viking metal u fagget" (sic). The internet is a Janusian prostitute. THERE, I SAID IT.
Besides, this is an opinion blog. I am beholden to no one but my own sweet self. So if I say Viking metal is a genre, it's a genre. If you want to argue that, please feel free to do so in the comments, pre-supposing if you do that there is an implied EULA which states that any comments left on Also, Wolves or any of its sister sites (probably also named Also, Wolves) are subject to minute dissection and probable sarcastic (yet witty) mockery by the creator and/or the entire internet. No saving throws.