John Williams was born in Cornwall in 1861. He inherited Caerhays Castle in 1880, but did not live there until 1884. He was involved in both local and national government and was a benefactor for many local causes. In the late-19th and early-20th centuries he established an informal or ‘wild' gardening style. He began planting rhododendrons on the site in the 1880s, and by 1917 more than 250 species and natural varieties of rhododendron could be found at Caerhays. He was a founder member of the Rhododendron Society in 1916. He was also involved in the hybridization of camellias and daffodils.