A Promised Land sold 66,531 copies in the week to 19 December, not enough for the former US president to match his wife Michelle Obama’s feat two years ago, when she took the UK’s Christmas crown. The last adult novel to be Christmas No 1 was Dan Brown’s The Lost Symbol in 2009. Osman also beat David Walliams, who has been the No 1 author for three of the last four Christmases. His latest children’s novel, Code Name Bananas, which is set during the second world war, came in third having sold 55,129 copies, while Pinch of Nom food bloggers Kate Allinson and Kay Featherstone’s third cookbook, Quick and Easy, came in fourth.