Bābak Khorram-Din (Persian: بابک خرمدین‎, alternative spelling: Bābak Xorramdin; 795, according to some other sources 798— January 838 ) was one of the main Persian revolutionary leaders of the IranianKhorram-Dinān ("Those of the joyous religion"), which was a local freedom movement fighting the Abbasid Caliphate. Khorramdin appears to be a compound analogous to dorustdin (orthodox) and Behdin "Good Religion" (Zoroastrianism), and are considered an offshoot of neo-Mazdakism. Babak's Iranianizing rebellion, from its base in Azarbaijan in northwestern Iran, called for a return of the political glories of the Iranian past. The Khorramdin rebellion of Babak spread to the Western and Central parts of Iran and lasted more than twenty years before it was defeated. Babak's uprising showed the continuing strength in Azerbaijan of ancestral Iranian local feelings.

babak is the arabicised form of the Iranian name Pāpak. Babak means "father" in Persian.

Bābak was born into a Persian family in Āzerbāijān (northwestern Iran) close to the city of Artavilla (modern Ardabil). According to Wāqed ben Amr Tamimi, the oldest biographer on Babak, Bābak's father was a Persian from Madā'īn (formerly known as Ctesiphon, capital of Sassanian Persian Empire, 35 km south of modern Baghdad in Iraq) who left for the Āzarbāijān frontier zone and settled in the village of Balālābād in the Maymadh district. According to Fasīh, his mother - a native Persian of Āzarbāijān - was known as Māhrū (meaning Moon-Face/Belle in Persian).

System of a Down, also known by the acronym SOAD and often shortened to System, is a rock band from Southern California, formed in 1994. It consists of Serj Tankian (lead vocals, keyboards, rhythm guitar), Daron Malakian (guitar, vocals), Shavo Odadjian (bass, background vocals) and John Dolmayan (drums).

The band achieved commercial success with the release of five studio albums; from which three debuted at number one on the Billboard 200. System of a Down has been nominated for four Grammy Awards, and won the award in 2006 for Best Hard Rock Performance for the song "B.Y.O.B.". The group went on hiatus in August 2006, but reunited in November 2010, embarking on a worldwide tour in 2011.

Serj Tankian, Daron Malakian, and Shavo Odadjian all attended Rose and Alex Pilibos Armenian School while children, although because of their eight-year age difference they did not meet until 1992 while working on separate projects at the same recording studio. They formed a band named Soil with Tankian on vocals and keyboards, Malakian on vocals and guitar, Dave Hakopyan (who later played in The Apex Theory/Mt. Helium) on bass and Domingo "Dingo" Laranio on drums. The band hired Shavo Odadjian (another Rose and Alex Pilibos alumnus) as manager, although he eventually joined Soil as rhythm guitarist. After three years, only one live show, and one jam session recording, Hakopyan and Laranio quit the band, feeling that it was not going anywhere.