Why is the Queen Mother wearing a conical beaded cap? Find out at Christie's South Ken's sale of tribal art
Well-heeled Europeans will be ploughing through Old Masters in Baden-Baden, Germany, this week, in what Sotheby's claims as the biggest fine art auction in living memory. The Margrave of Baden, cousin of Prince Charles, is selling 25,000 heirlooms - paintings, furniture, ceramics, silver, textiles - crammed until now into all 105 rooms and corridors of the Neues Schloss, one of the family's three castles. The 15-day sale, until Saturday 21 October, is expected to raise pounds 13m.

The House of Baden is selling its family silver because of a decline in the engineering and forestry industries. that made it rich. Meanwhile, in London, impoverished Brits have a chance to pick up cheap tribal art from former colonies that made Britain rich.

The current Africa '95 season of events and exhibitions has sparked a new interest in tribal art. If prices are to rise, then Christie's South Kensington's bi-annual minor sale, Tuesday (10.30am), should see some competitive edge. But it may be some time before the new wave of interest raises prices across the board. A Nigerian Benin cast, brass Queen Mother head is in the sale without estimate - which means that less than pounds 100 is expected. (It is their Queen Mother, by the way, not ours: she wears a conical beaded cap).

Such castings were made by the "lost wax" method, in which the narrow cavity vacated by molten wax is filled with molten brass. An example dating from 1500 or earlier is expected to fetch pounds 60,000-pounds 80,000 at Christie's bi-annual major tribal art sale in December. Why the difference in value? South Ken's Queen Mum head is the product of a Benin craft revival that began supplying the western art market in the Fifties. It is not regarded as pukka tribal art but "airport art", a reference to airport souvenir shops.

American collectors, who provide more than 60 per cent of the London auction income from tribal art, will not touch such things. Which is good news for British collectors. There are some wonderful things for sale. A big, confident Nigerian Gomai pottery vessel with naked female on the shoulder, probably made in the Forties or Fifties and expected to fetch pounds 400-pounds 600. Two Peruvian pots of the Chimu people, who flourished AD1200-1400, are without estimate, as is a North American Indian bead "glengarry" or smoking hat, probably made for Victorian travellers.

Christie's third annual sale of German and Austrian art is on Wednesday (2pm) and seems to have become one of the season's fixtures. Nowadays, museums are eager to fill gaps in their German Expressionist collections while they are still cheaper than their French equivalents. Last year's sale produced artists' records for Schmidt-Rottluff, Liebermann, Jawlensky, Corinth and Kirchner.

Wizard wheeze by Sotheby's: a "food and drink" sale, actually the sale of Swiss chef Anton Mosimann's collection of 19th-century cooking ranges, posters, cook books and his own menu cards: Thursday (10.30am).