Some of the world's most powerful people are gathering near London for a shadowy annual gathering that has attained legendary status for anticapitalist protesters and conspiracy theorists.

Google executive chairman Eric Schmidt, Amazon CEO Jeff Bezos, International Monetary Fund chief Christine Lagarde and former U.S. Secretary of State Henry Kissinger are on the guest list for the Bilderberg meeting at Watford's Grove Hotel.

The annual forum for prominent politicians, thinkers and business leaders has been held since 1954 in either Europe or North America. No minutes are taken, there is no media access and the public is kept away by a large security operation.

Protesters, who see a global ruling elite at work in the secretive talkfest, are planning a presence outside the hotel until the conference ends Sunday.