These kinds of bands are usually lumped together since they tend to share a lot of thematic overlap
Windir, Bran Barr, Manegarm, Ensiferum, Arkona (the Russian one), Skálmöld, Heidevolk, Primordial, Mael Mordha, early Enslaved, Falkenbach, Folkvang, Forefather, Graveland, Summoning, Moonsorrow, Murg, Nechochwen, Nornir, Norrhem, Obscurity, Panphage (highly recommended), Runespell, Finntroll, Thyrfing, Thrudvangar, Vintersorg, Waylander, Winterfylleth, Ygg