Epica is a Dutch symphonic metal band founded by guitarist and vocalist Mark Jansen after his departure from After Forever. Originally formed as a symphonic metal band with gothic influences, Epica later incorporated strong death metal elements into their sound. Starting with their third album, progressive metal influences also became evident. Additionally, the band often incorporates thrash metal and groove metal riffs, black metal elements (particularly in drumming techniques), power metal sections, and influences from Arabic music. Some songs also incorporate electronic elements, djent transitions, and folk metal melodies inspired by Middle Eastern, Chinese, and Celtic traditions.

Epica is also known for its attention to vocal melodies, which contrast with the heavy instrumentation by weaving catchy, sophisticated, and emotionally expressive lines. The band's sound prominently features a combination of soprano vocals, performed by Simone Simons, and growled vocals, provided by Mark Jansen. They primarily write their own lyrics, which explore philosophical, psychological, spiritual, moral, scientific, environmental, socio-political, global, topical, and personal themes. Epica is also recognized for its extensive use of orchestral arrangements and operatic choirs.

In 2003, Epica released its debut album, The Phantom Agony, through Transmission Records. Consign to Oblivion followed in 2005, debuting at No. 12 on the Dutch charts. After Transmission's bankruptcy, the band signed with Nuclear Blast and released its third studio album, The Divine Conspiracy, in 2007, which charted at No. 9 in the Netherlands. Design Your Universe (2009) brought the band even greater success, debuting at No. 8 on the Dutch Albums Chart and charting across Europe, while also receiving widespread critical acclaim. Epica's fifth studio album, Requiem for the Indifferent, was released in 2012. Well received by critics, it achieved international success, entering the US Billboard 200 at No. 104 and Japan's Oricon Albums Chart at No. 172.

At the beginning of May 2014, the band released their sixth album, The Quantum Enigma, which was a huge international success, debuting at No. 110 on the US Billboard 200 and peaking at No. 4 in Epica's homeland of the Netherlands. In June 2015, Epica was awarded the Music Export Award, which is given to the Dutch act with the most international success in the past year. Their seventh album, The Holographic Principle, was released in September 2016 to continued international success, matching the peak chart position set by its predecessor in the Netherlands. The band released their eighth album, Omega, in February 2021.

In early 2002, at 23 years old, Mark Jansen left After Forever due to creative differences. He then began searching for musicians to create a more classical/symphonic music project, initially named Sahara Dust. In late 2002, the band approached Helena Iren Michaelsen (from Trail of Tears) to be its frontwoman, but she was soon replaced by Simone Simons, who was Jansen's girlfriend at the time. The band's lineup was completed by guitarist Ad Sluijter, drummer Jeroen Simons, bassist Yves Huts, and keyboardist Coen Janssen. The name was later changed to Epica, inspired by Kamelot's album of the same name.

Epica then assembled a choir (consisting of two men and four women) and a string orchestra (comprising three violins, two violas, two cellos, and an upright bass) to perform with them. Still under the name Sahara Dust, they produced a two-song demo titled Cry for the Moon in 2002. As a result, they were signed to Transmission Records.

The Phantom Agony is the first full-length studio album by Epica. It is the first album recorded by guitarist Mark Jansen after his departure from the band After Forever. The album was produced by Sascha Paeth (known for having produced bands such as Angra, Rhapsody of Fire, and Kamelot) and released in June 2003. In this album, Mark Jansen continues the collection of songs that make up "The Embrace That Smothers." The first three parts can be found on Prison of Desire (2000), After Forever's debut album, and the following three parts can be found on The Divine Conspiracy (2007), Epica's third album. These songs address the dangers of organized religion. The song "Façade of Reality" on the album was written about the September 11 attacks and includes fragments from speeches by Tony Blair.

The album was followed by three singles: “The Phantom Agony,” “Feint,” and “Cry for the Moon.”