First Aid Kit is a Swedish folk duo composed of sisters Johanna (born October 31, 1990) and Klara Soderberg (born January 8, 1993), whose close vocal harmonies and woodsy, folk-influenced songwriting take influence from the likes of Fleet Foxes and Joanna Newsom. Hailing from Enskede, a southern suburb of Stockholm, the siblings began composing songs in 2007. Their 2008 YouTube video cover of the song "Tiger Mountain Peasant Song" by Fleet Foxes spread their name rapidly on the Internet. The sisters subsequently appeared alongside Fleet Foxes performing the song in a concert in the Netherlands.

Starting out in 2007, the sisters sent a demo tape of their home-recorded "Tangerine" to a Swedish radio station, which gave it airplay that summer. Later that year the duo signed to Rabid Records, a label co-owned by the Swedish electronic duo The Knife. April 2008 saw the release of the debut EP Drunken Trees in Sweden. The London-based Wichita Records label reissued the EP one year later, bolstering its track list with a cover of Fleet Foxes' "Tiger Mountain Peasant Song" and videos of three songs performed live in a Swedish forest. During their early years the duo had a collection of songs posted on the social networking site MySpace, one of which was "Cross Oceans", a re-recording of which later appeared on Drunken Trees.

They released their debut album, The Big Black & The Blue, in 2010; the release was followed by an extensive tour (around 100 shows) of the USA, Canada, Australia, New Zealand and parts of Europe, headlining the Thursday night at the Primavera Festival in Barcelona. After playing a concert in Nashville the duo was approached by Jack White, who requested them to record a single for his Third Man Records series. In February 2011 the duo collaborated with Bright Eyes during their performance of "Lua".