Finnish act Ensiferum was founded in 1995 by Markus Toivonen (guitar), Sauli Savolainen (bass) and Kimmo Miettinen (drums). Jari Mäenpää joined soon after on vocals and second guitar player. For the band's name, they took the Latin word "ensiferum", which means "sword bearer". In 1997, the first demo soon followed, containing three songs.
In 1998, founding members Savolainen and Miettinen left the band to be replaced by Jukka-Pekka Miettinen (Kimmo's younger, 14 year old, brother) and Oliver Fokin drums. In January 1999, a second demo was recorded. In November 1999 a third demo, Hero in a Dream, was also recorded, which was successful in obtaining a record deal with 'Spinefarm Records'. The logo that now appears on all the bands releases was designed for that third demo by Tuomas Tahvanainen, who also designed the logos for the earlier demos. In 2001, their first album, the self-titled Ensiferum, arrived. Soon after, Meiju Enho joined on as keyboard-player.
The second album, Iron arrived in 2004, but shortly after, Jari was fired because of conflicts between his studio work on his side project, Wintersun and touring with Ensiferum. For the subsequent tour with Finntroll, Petri Lindroos from Norther replaced him and, later, became a member of the band. In December of that year, Jukka-Pekka also left the band to be replaced by Sami Hinkka (ex-Rapture). More membership changes were coming down the pipe, for in 2005, Oliver also left iand was replaced by Janne Parviainen.
The new Ensiferum line-up entered the studio later that year to record an EP called Dragonheads, that was released in February of 2006. As well as the title track, it also contained two reworked demo songs; an Amorphis cover and a short rendition of the Kalevala melody, as well as a medley of three traditional Finnish songs.
In June 2006, Ensiferum released their live DVD, 10th Anniversary Live on 31 December 2005.
Victory Songs, the next album, came on 20 April 2007. A single titled One More Magic Potion (after the track of the same name) was released on 7 February.
On 10 September 2007, Meiju Enho made it known he would leave the band. This was posted in a bulletin on their MySpace page and later confirmed on their website. The band used the services of Emmi Silvennoinen of Exsecratus as a touring fill-in. She later became a permanent member of the band during the recording of the upcoming From Afar album.
Ensiferum then headlined the Paganfest tour in Europe and North America in 2008 along with Týr and Eluveitie, with Moonsorrow and Korpiklaani joining for the European part of the tour; Turisas in North America. They also supported Megadeth on the opening night of their United Abominations Tour of Duty European tour.
Shortly before their Russian tour in 2008, vocalist/guitarist Petri Lindroos fell "seriously ill" and was unable to participate. The band hired ex-bassist Jukka-Pekka Miettinen to assume Lindroos' guitar duties, while bassist Sami Hinkka took over his lead vocal duties for the tour.
Ensiferum released their fourth studio album, From Afar, on 9 September 2009 on 'Spinefarm Records'. A special limited edition of the album includes a cover of Swedish folk rock group Nordman with guest vocalist Heri Joensen of Faroese band Týr. Following the release, the group embarked on a European tour with Estonian folk metal band Metsatöll and Finnish melodic death metal band Tracedawn.
In October 2010, the act embarked on their first ever South African tour. This tour consisted of four shows in two cities, accompanied by numerous local metal bands Riddare av Koden, Empery and All Forlorn. The final show, at The Black Dahlia in Johannesburg was filmed to potentially appear on their next live DVD.
In early 2011 Ensiferum embarked on The Ugly World Tour 2011 with label mates Children of Bodom, Amon Amarth and Machinae Supremacy supporting them for segments of their tour in the U.S.A and Canada.
Unsung Heroes followed in 2012, with One Man Army following in 2015 now on the 'Metal Blade' label.
On 31 March 2016 Emmi Silvennoinen would take a leave of absence from the band because of personal issues. Netta Skog was confirmed as her permanent replacement.