Delain is a Dutch symphonic metal band formed in 2002 by former Within Temptation keyboardist Martijn Westerholt and Charlotte Wessels.

In 2001, Martijn was forced to leave Within Temptation after contracting Pfeiffer's disease. In 2002, he joined with Charlotte Wessels to form Delain. In the same year, they independently released the demo Amenity. However, it was not until 2005 that they were signed to Roadrunner Records. At the time, the band was envisioned as musical project featuring a host of guest musicians, and not as a live band.

Lucidity brought to fruition Martijn's dream of a musical project, featuring many well-known musicians from the metal community: Marco Hietala from Nightwish and Tarot (bass, vocals), Liv Kristine from Leaves' Eyes (vocals), Ariën van Weesenbeek from ex-God Dethroned, Epica (drums), Ad Sluijter from ex-Epica (guitar), George Oosthoek (growling) and Guus Eikens, both former members of Orphanage, Sharon Den Adel from Within Temptation (vocals) and Jan Yrlund from Imperia (guitar).

Sharon Janny den Adel (born 12 July 1974, in Waddinxveen, South Holland, Netherlands) is a Dutch singer and composer, best known as the lead vocalist and one of the main songwriters in the Dutch symphonic metal/rock band Within Temptation. She has performed with various bands since she was 14, including a blues rock band called Kashiro, before forming Within Temptation with Robert Westerholt in 1996.

Together with her partner, Robert Westerholt, den Adel is one of the founding members of Within Temptation. She has defined their work as epic and cinematic. Her vocals play a major role in the band's sound, despite having never received formal vocal training. Den Adel sings in the mezzo-soprano range but her vocal quality is light and lyric despite her range. Before Within Temptation became famous, she worked for a fashion company, leaving after the band found success with their hit single "Ice Queen". She utilises her fashion expertise by designing her stage costumes and the band's merchandise.About.com described den Adel as a "versatile and skilled singer who is equally adept at singing powerfully with a full orchestra and choir as she is at singing quietly and emotionally with just a piano."

Johanna Charlotte Wessels (born 13 May 1987) is the lead vocalist of the Dutch symphonic metal band Delain. She was previously a member of gothic metal band To Elysium, before the band's split. She formed Delain in 2005 with ex-Within Temptation pianist Martijn Westerholt.

Charlotte has been trained in both jazz singing and classical singing. She was first trained in jazz, but later her instructor suggested classical singing to her. However, Charlotte has stated that she found classical training to be very restrictive, and so she likes to do something "in between the classical and the jazz stuff, and if you look at classical music with high vocal lines, then you kind of get to gothic very soon!"