John Josiah Guest

John Josiah Guest (February 2, 1785 - November 26, 1862) was an engineer and entrepreneur. Born Dolwais, Merthyr Tydfil, Wales, son of Thomas Guest, a partner in the Dolwais Iron Company. Guest was educated at Bridgenorth and Monmouth Grammar Schools before learning the trade of iron making in his father's foundry at the hands of works manager John Evans. He was renowned for his ability to roll a bar of steel or cut a tram of coal as well as any of his father's workmen.

On his father's death in 1807, John inherited his share of the company and developed the business, becoming sole owner of the works in 1815. In 1817 he married Maria Rankin but their marriage was short lived, Maria dying just nine months later. He subsequently married Lady Charlotte Elizabeth Bertie, daughter of Albermarle, ninth Earl of Lindsey.

Guest was elected member of parliament for Honiton, Devon in 1825, holding the seat until defeated by Sir G. Warrander in 1831. His public works included a school at Dolwais, designed by Sir Charles Barry. He was a Fellow of the Royal Society and a Member of the Institution of Civil Engineers.

He died in 1852, leaving five sons and five daughters, the Dolwais Iron Company having become the largest producer of iron in the world.