written, produced and directed by Mark Davis ; a NOVA production by MDTV Productions for WGBH/Boston in association with National Geographic Channel International
an ArtMattan Productions release ; Periscope Productions and BBC, ZDF, Arte, IKON, VRT, RTBF, YLE, and in association with History Television, SBS Television, and Danmarks Radio ; produced by Paul Pauwels, Nick Fraser, Olaf Grunert, Wessel van der Hammen, Philippe Van Meerbeck, Bill Binnemans, and Iikka Vehkalahti ; written and directed by Peter Bate