Secret Facts

Jackie Kennedy Onassis, despite her iconic public image, maintained a private habit as a heavy smoker, consuming up to three packs a day for over 40 years.

A 29-year-old London stockbroker secretly organised 8 trains that smuggled 669 Jewish children out of Nazi-occupied Czechoslovakia in 1939 - forging documents, bribing officials, finding British families - then told nobody for 50 years. In 1988, the BBC invited him to sit in a studio audience without explaining why. The host asked anyone who owed their life to Nicholas Winton to stand. The entire row behind him rose. He had no idea they were there.

Michelangelo was sentenced to death in 1530. He hid for two months in a secret coal vault, drawing on the walls. Those drawings - attributed to him but still debated - lay plastered over for 445 years. In 1975, a director found them under a trapdoor. They are still on the walls.