Geldof is now more known for his charity work than his music

Geldof, who originally found fame as the lead singer of the Boomtown Rats, will kick off the cultural celebration in the city of Segovia on 21 September.

The move to Spain is a new take on the festival, dubbed "the Woodstock of the mind" and traditionally held in the small Welsh town of Hay-on-Wye.

Authors Martin Amis, Ian McEwan and Fernando Savater will also attend.

Geldof will also give a talk about his work as the founder of Live Aid and working with the leaders of the G8 group of the world's wealthiest nations.

Going abroad

Other attractions will include two photographic exhibitions from the Institute of Spanish Historical Heritage, as well as works by Colombian artist Fernando Botero.

Al Gore is one of the big names to have attended the festival this year

A selection of sculptures from artists including Martin Chirino, Francisco Leiro and Manolo Valdes will also be on display.

It is the festival's second trip abroad this year - a session took place in the Colombian city of Cartagena in January.

Former US President Bill Clinton gave the Hay festival its "Woodstock of the mind" tagline - a reference to the seminal 1969 concert in New York which featured acts such as The Who, Janis Joplin and Jimi Hendrix.