In London, author and amateur auctioneer Jeffrey Archer sells the watch used to clock Roger Bannister's four-minute mile and 'Iron Lady' Margaret Thatcher's famous black Asprey bag.

A London auction asks for £20million for George Stubbs' Gimcrack on Newmarket Heath and an emerald and diamond tiara goes on sale in Geneva with a staggering estimate of $10million.

As leading auction houses open their doors, more than 100 pianos go on sale at Conway Hall and Sotheby's offers a Francesco Guardi view of Venice - worth around £20million.