Fate/Zero is a Japanese light novel series written by Gen Urobuchi, illustrated by Takashi Takeuchi, and is a prequel to all routes in Type-Moon's visual novel, Fate/stay night. It was published by Type-Moon with four volumes released between December 2006 and 2007. The story centers on the Fourth Holy Grail War, a magical tournament held in Fuyuki City, Japan, where seven mages known as Masters summon Servants, reincarnations of legendary souls and heroes from all across time, where they fight in a deadly battle royale where the winner obtains the Holy Grail, a legendary magical chalice capable of granting wishes. The main protagonist of Fate/Zero, Kiritsugu Emiya, joins the tournament on behalf of his wife's family, the Einzberns.
An anime adaptation was produced by Ufotable, the first season of which aired from October 1 to December 24, 2011, and the second season of which aired from April 7 to June 23, 2012. A manga adaptation was published by Kadokawa Shoten between 2011 and 2017. Dark Horse Comics licensed the manga and released it in English in North America.
Fate/Zero was praised for its animation, themes, characters, soundtrack, and story. The series has also been a commercial success, selling over 40,000 Blu-ray box-sets and winning several awards at the Newtype Anime Awards, including "Title of the Year".