The heavy metal festival, Sonisphere, is returning after a 2-year absence to Knebworth next year, and with a stellar line-up featuring Iron Maiden and Metallica. The festival will take place between July 4 and 6 2014.

Iron Maiden singer Bruce Dickinson said in a statement:

"We all grew up in England well aware of the importance of the legendary concerts at Knebworth, and scarily it all seems quite recent! Without being clichéd, it really is an honor and privilege to return to play there with the purpose of celebrating some of the finest moments in British rock history from inspirational bands like Pink Floyd, The Who, Zeppelin, The Stones and Genesis.

Metallica drummer Lars Ulrich meanwhile commented:

"This just works on all fronts: Metallica and Knebworth, Metallica by Request, Metallica and Iron Maiden.

"To be invited to co-headline the 40th anniversary celebration at the legendary Knebworth House is truly a mindfuck. Considering the iconic bands whose performances at Knebworth are part of rock and roll history, it’s not only a next level honour, but a somewhat humbling undertaking.

"And what could be more fitting on our third Knebworth go-around than to play an all-request set, chosen entirely by the fans? We are soooo excited about the limitless possibilities of our friends picking what songs Metallica get to perform on this forthcoming evening from the nearly 140 songs we’ve recorded throughout our ride.

"Who knows what crazy challenges will be thrown our way? Maybe a song that has never been performed live before? Maybe a few deep cuts that haven’t been aired in ages? Maybe a couple of your toe-tapping favorites? An obscure cover? Whatever happens, it will be unique, it will be special, and it’s all up to you."

Watch The History of Iron Maiden below: