Poet and painter Adrian Henri claimed to have organized the first happenings in England in Liverpool in 1962, taking place during the Merseyside Arts Festival. The most important event in London was the Albert Hall "International Poetry Incarnation" on June 11, 1965, where an audience of 7,000 people witnessed and participated in performances by some of the leading "avant-garde" young British and American poets of the day (see British Poetry Revival and Poetry of the United States). One of the participants, Jeff Nuttall, went on to organize a number of further happenings, often working with his friend Bob Cobbing, sound poet and performance poet.