Smithson never married and had no children; therefore, when he wrote his will, he left his estate to his nephew, or his nephew's family if his nephew died before Smithson. If his nephew were to die without heirs, however, Smithson's will stipulated that his estate be used "to found in Washington, under the name of the Smithsonian Institution, an establishment for the increase and diffusion of knowledge among men". He died in Genoa, Italy on 27 June 1829, aged 64. Six years later, in 1835, his nephew died without heir, setting in motion the bequest to the United States. In this way Smithson became the patron of the Smithsonian Institution in Washington, D.C. despite having never visited the United States.