Ian Hamilton masterminded one of the most daring heists of the last century

As treasures went, this one was no beauty. It was an oblong block of red sandstone, 26 inches long by 16.7 wide by 10.5 deep, rough-hewn and chisel-pocked. One face was incised with a crude cross, and two iron rings on chains were set into the ends. By young Ian Hamilton’s estimate—for he had borrowed book after book on it from the Mitchell Library in Glasgow, where he was studying law at the university—it weighed four hundredweight: in fact it weighed 336lb, or 152 kilos. It was also crammed tightly under the ancient wooden coronation chair of the kings and queens of England in Westminster Abbey. All this made it difficult to abscond with. But that was what he meant to do.