Twenty men with a past

Articles are: Julian Assange by Thomas Paine; David Beckham by Adonis; Silvio Berlusconi by Garibaldi; Harold Camping by Nostradamus; Simon Cowell by PT Barnum; James Dyson by George Stephenson; Chris Evans by Alvar Liddell; Colin Firth by Emil Jennings; Bill Gates by Charles Babbage; Bob Geldof by William Wilberforce; Damien Hirst by Caravaggio; Boris Johnson by Dick Whittington; Nelson Mandela by Toussaint Louverture; Peter Mandelson by Niccolo Machiavelli; Paul McKenna by Franz Mesmer; Rupert Murdoch by Randolph Hearst; Vladimir Putin by Lavrentiy Beria; Nicolas Sarkozy by Napoleon Bonaparte; David Walliams by Will Kemp; Mark Zuckerberg by Karl Marx.