Joseph Hardcastle (1752–1819) was one of the founders of 'The Missionary Society', later the London Missionary Society, to which he devoted a great deal of time and money, becoming the First Treasurer.
He was born in Leeds, where he lived until the age of 15, at which point he moved to London to join his uncle's business. He eventually became a Merchant, still based in London. During his time in London he lived at Old Swan Stairs, before moving to Hatcham House in Deptford, then a rural Surrey village, which is now the New Cross Gate area of Lewisham.
The slavery abolitionist, Thomas Clarkson was a frequent guest at Hatcham House. Here Clarkson wrote a great part of his 'History of the Abolition of the Slave Trade', and met his future wife, a niece of Mrs Hardcastle. Joseph Hardcastle was especially active in arranging missionary expeditions to Africa, and created schemes whereby missionary work could be self-funding by selling artifacts brought back by the missionaries themselves.
The story of Joseph's life was published in "Memoir of Joseph Hardcastle Esq., the first Treasurer of the London Missionary Society: A Record of the Past for his Descendants", which was written by his last surviving daughter, Emma Corsbie Hardcastle, and published in 1860. A number of roads in the modern New Cross Gate reflect his time, most notably Joseph Hardcastle Close.