 In 1843 , the property was bought by businessman William Gibbs , who made his fortune in the family business , Antony Gibbs & Sons . From 1847 the firm had an effective monopoly in the import and marketing to Europe and North America of guano from Peru as a fertilizer . This was mined by indentured Chinese labour on the Chincha Islands in conditions which the Peruvian government acknowledged in 1856 had degenerated " into a kind of Negro slave trade " . The firm 's profits from this trade were such that William Gibbs became the richest non @-@ noble man in England . 
