Ensiferum means "Sword Bearer". 'Ensis' is a third declension noun meaning Sword, and 'Ferum' is from an irregular verb meaning "to carry" (like "ferry"). Markus Toivonen found the word in a Latin dictionary when the band were starting out and decided it was an ideal name.
Ensiferum were founded as a three-piece by Markus Toivonen, Sauli Savolainen and Kimmo Miettinen. They began mostly as a cover band before persuading Jari Mäenpää to join as vocalist and second guitarist a year later.
Frontman Jari Mäenpää quit in 2004 after creating his own project, Wintersun. Studio time for Wintersun recordings clashed with an Ensiferum tour, so Mäenpää quit Ensiferum. Petri Lindroos of Norther was brought in, inititally to cover for live dates, and eventually agreed to join permanently. At this point the band's vocal duties were split as Lindroos performed only the harsh singing while Markus Toivonen and Sami Hinkka took over the clean vocals. Toivonen is now the only founding member left in the band.
Markus Toivonen never played in Scent of Flesh - there are two different persons with the same name.
Petri Lindroos was forced to miss a few tour dates in November 2008 due to illness. Former bassist Jukka-Pekka Miettinen filled in as guitarist while Sami Hinkka took up harsh vocal duties.