The Heart of Everything is the fourth studio album by Dutch symphonic metal band Within Temptation, released by GUN Records on 12 March 2007 in Europe. It was released in North America on 18 June 2007 by Roadrunner Records. The album follows the symphonic metal sound the band had been improving and deepening until then, and is considered by lead vocalist Sharon den Adel as the album in which the band finally managed to achieve this kind of sound.
 
The album originated a total of five singles. The first and most successful one, "What Have You Done", was released on February 14 and was met with moderate chart success across Europe.The song eventually became one of the band's signature songs, being played in almost every concert.The album itselft was also met with commercial and critical success, earning positive reviews from publications such as Metal Hammer, all music and PopMatters. The album opened at number 1 on the Dutch Charts and also was the first to enter a Billboard chart. To promote the album, the band embarked on their first world tour, entitled The Heart of Everything World Tour, visiting countries in Europe, North America, South America, and Asia.