A new series opens with bidders shuttling between Sotheby's and Christie's in New York for the annual May sales of post-war and contemporary art.

At Sotheby's in London two ancient Scottish families are having a clear-out. Their treasures include a sword said to have been used at the Battle of Culloden.

A mega sale by Christie's of contemporary art includes a work by Peter Doig originally bought for \u163\'5f15,000. What will it fetch now? Plus, a rare Rothko goes under the hammer.