Chéri Samba, who was included in the 2007 Venice Biennale, began his career as a billboard sign painter; his works often record life around his hometown of Kinshasa in the Democratic Republic of Congo. This painting, which was bought in 2011 by a collector of Congolese art, is inscribed with text written in both French, the official language of the DRC, and Samba’s mother tongue, Kikongo. The word bubble at the bottom of the canvas—a ‘Samba signature’—begins, “every nation is exalted by their own language”, a pointed reference to having pride in your native tongue. Chéri Samba, Le collège de la Sagesse (2005). Modern and Contemporary African Art, Bonhams, London, 3 October. Estimate: £30,000-£40,000