Liv Kristine Espenæs (born 14 February 1976) is a Norwegian singer who has performed and composed songs mostly for various subgenres of heavy metal music.

Kristine was born in Stavanger, and joined the Norwegian gothic metal band Theatre of Tragedy in 1994 as a backup singer, but was soon sharing lead vocals duties with Raymond István Rohonyi.

[10] Kristine helped to pioneer the beauty and the beast vocals approach, later used by many other successful bands such as Tristania, After Forever, Epica and Within Temptation in their beginnings.

The term "beauty and the beast" refers to an aesthetic contrasting "angelic" female vocals with male growls or aggressive singing.

[12] The piano was replaced by electronic keyboards while Raymond Rohonyi opted to discard his death growls in favor of a "soft, spoken, sometimes whispering voice".

[13] The music was more clean and soft,[13] "stripped of guitar harshness" but with a "near flawless execution" that "prompted many European critics to award Aégis perfect review scores".