In 1752 Princess Augusta instructed her head gardener, John Dillman, to "compleat all that part of the Garden at Kew that is not yet finished in the manner proposed by the Plan and to keep all that is now finished". With the very able help of the Earl of Bute, the development of Kew as a serious botanic garden was well under way, driven by Bute's desire to have a garden which would contain all the plants known on Earth". Princess Augusta was, in effect, the founder of the botanic gardens at Kew. Throughout its history, the Royal Botanic Gardens, Kew has made important contributions to increasing the understanding of the plant kingdom with many benefits for mankind. Today it is still first and foremost a scientific institution. With its collections of living and preserved plants, of plant products and botanical information, it forms an encyclopaedia of knowledge about the plant kingdom. Recognised as a UNESCO World Heritage Site in 2003, Kew's rich horticultural and scientific history is interwoven with royal heritage and its historic importance. It houses the earth's largest and most diverse botanical collections, including reference collections.